[500962] Support and test incremental for object add/delete

36 files changed, 902 insertions, 562 deletions

diff --git a/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiCG2JavaVisitor.java b/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiCG2JavaVisitor.java
index 2d8cb3f43..8e716744d 100644
--- a/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiCG2JavaVisitor.java
+++ b/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiCG2JavaVisitor.java
@@ -266,7 +266,8 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		js.append(");\n");
 		//
 		if (isIncremental) {
-			js.append("objectManager.created(");
+			js.append(QVTiGlobalContext.OBJECT_MANAGER_NAME);
+			js.append(".created(");
 			js.appendThis(getThisName(cgRealizedVariable));
 			js.append(", ");
 			js.appendValueName(cgRealizedVariable);
@@ -392,7 +393,8 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		CGValuedElement cgInit = getExpression(QVTiCGUtil.getOwnedInitValue(cgPropertyAssignment));
 		EPackage ePackage = ClassUtil.nonNullModel(eStructuralFeature.getEContainingClass().getEPackage());
 		if (isIncremental || ((SetStatement)cgPropertyAssignment.getAst()).isIsNotify()) {
-			js.append("objectManager.assigned(");
+			js.append(QVTiGlobalContext.OBJECT_MANAGER_NAME);
+			js.append(".assigned(");
 			if (isIncremental) {
 				js.appendThis(getThisName(cgPropertyAssignment));
 				js.append(", ");
@@ -414,7 +416,8 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		CGValuedElement cgInit = getExpression(QVTiCGUtil.getOwnedInitValue(cgPropertyAssignment));
 		EPackage ePackage = ClassUtil.nonNullModel(eStructuralFeature.getEContainingClass().getEPackage());
 		if (isIncremental || ((SetStatement)cgPropertyAssignment.getAst()).isIsNotify()) {
-			js.append("objectManager.assigned(");
+			js.append(QVTiGlobalContext.OBJECT_MANAGER_NAME);
+			js.append(".assigned(");
 			if (isIncremental) {
 				js.appendThis(getThisName(cgPropertyAssignment));
 				js.append(", ");
@@ -661,6 +664,11 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		ElementId elementId = cgFunction.getTypeId().getElementId();
 		js.append(" {\n");
 		js.pushIndentation(null);
+		//		if (isIncremental) {
+		//			js.append("super(\"");
+		//			js.append(getFunctionName(cgFunction));
+		//			js.append("\");\n");
+		//		}
 		//					js.appendCastParameters(localContext2, cgParameters);
 		//					JavaDependencyVisitor dependencyVisitor = new JavaDependencyVisitor(localContext2, null);
 		//					dependencyVisitor.visit(body);
@@ -771,6 +779,11 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		String functionName = getFunctionName(cgFunction);
 		js.append(" {\n");
 		js.pushIndentation(null);
+		if (isIncremental) {
+			js.append("super(\"");
+			js.append(functionName);
+			js.append("\");\n");
+		}
 		EClassifier eClassifier = ClassUtil.nonNullState(cgShadowExp.getEcoreClassifier());
 		if (eClassifier instanceof EDataType) {
 			CGShadowPart cgShadowPart = ClassUtil.nullFree(cgShadowExp.getParts()).get(0);
@@ -877,6 +890,11 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		js.appendIsRequired(true);
 		js.append(" [] boundValues) {\n");
 		js.pushIndentation(null);
+		if (isIncremental) {
+			js.append("super(\"");
+			js.append(functionName);
+			js.append("\");\n");
+		}
 		js.appendThis(functionName);
 		js.append(".self = (");
 		js.appendClassReference(cgClass);
@@ -1069,7 +1087,8 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		if (isHazardous) {
 			EPackage ePackage = ClassUtil.nonNullModel(eStructuralFeature.getEContainingClass().getEPackage());
 			//
-			js.append("objectManager.getting(");
+			js.append(QVTiGlobalContext.OBJECT_MANAGER_NAME);
+			js.append(".getting(");
 			js.appendValueName(source);
 			js.append(", ");
 			js.appendClassReference(genModelHelper.getQualifiedPackageInterfaceName(ePackage));
@@ -1085,7 +1104,8 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		if (useGot) {
 			EPackage ePackage = ClassUtil.nonNullModel(eStructuralFeature.getEContainingClass().getEPackage());
 			//
-			js.append("objectManager.got(");
+			js.append(QVTiGlobalContext.OBJECT_MANAGER_NAME);
+			js.append(".got(");
 			//			if (localPrefix != null) {
 			//				js.append(localPrefix);
 			//				js.append(".");
@@ -1349,7 +1369,7 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 	protected void doMappingConnectionVariable(@NonNull CGGuardVariable cgFreeVariable) {
 		if (cgFreeVariable instanceof CGConnectionVariable) {
 			js.append("final ");
-			js.appendClassReference(true, Connection.class);
+			js.appendClassReference(true, isIncremental ? Connection.Incremental.class : Connection.class);
 			js.append(" ");
 			js.append(getValueName(cgFreeVariable));
 		}
@@ -1359,7 +1379,7 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 	}
 
 	protected void doMappingConstructor(@NonNull CGMapping cgMapping) {
-		List<@NonNull CGGuardVariable> cgFreeVariables = ClassUtil.nullFree(cgMapping.getOwnedGuardVariables());
+		Iterable<@NonNull CGGuardVariable> cgGuardVariables = QVTiCGUtil.getOwnedGuardVariables(cgMapping);
 		//		if (js.isUseNullAnnotations()) {
 		//			js.append("@SuppressWarnings(\"null\")\n");		// Accurate casts are too hard
 		//		}
@@ -1369,6 +1389,10 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		js.appendClassReference(true, isIncremental ? InvocationConstructor.Incremental.class : InvocationConstructor.class);
 		js.append(" ");
 		js.append(QVTiGlobalContext.CONSTRUCTOR_NAME);
+		if (isIncremental) {
+			js.append(", int ");
+			js.append(QVTiGlobalContext.INVOCATION_HASH_CODE_NAME);
+		}
 		js.append(", ");
 		js.appendIsRequired(true);
 		js.append(" Object ");
@@ -1378,23 +1402,27 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		//		if (isIncremental) {
 		js.append("super(");
 		js.append(QVTiGlobalContext.CONSTRUCTOR_NAME);
+		if (isIncremental) {
+			js.append(", ");
+			js.append(QVTiGlobalContext.INVOCATION_HASH_CODE_NAME);
+		}
 		js.append(");\n");
 		//
 		int i = 0;
-		for (@NonNull CGGuardVariable cgFreeVariable : cgFreeVariables) {
-			String valueName = getValueName(cgFreeVariable);
+		for (@NonNull CGGuardVariable cgGuardVariable : cgGuardVariables) {
+			String valueName = getValueName(cgGuardVariable);
 			js.append(valueName);
 			js.append(" = ");
 			//							js.appendClassCast(cgFreeVariable);
-			if (cgFreeVariable instanceof CGConnectionVariable) {
+			if (cgGuardVariable instanceof CGConnectionVariable) {
 				js.append("(");
 				//				js.appendClassReference(null, cgFreeVariable);
 				//				js.append(".Accumulator)");						// FIXME Embed properly as a nested typeid
-				js.appendClassReference(null, Connection.class);
+				js.appendClassReference(null, isIncremental ? Connection.Incremental.class : Connection.class);
 				js.append(")");						// FIXME Embed properly as a nested typeid
 			}
 			else{
-				js.appendClassCast(cgFreeVariable);
+				js.appendClassCast(cgGuardVariable);
 			}
 			js.append("boundValues[" + i++);
 			js.append("];\n");
@@ -1413,8 +1441,10 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 				js.appendClassReference(constructorClass);
 				js.append("(invocationManager, ");
 				js.appendString(QVTiCGUtil.getName(cgMapping));
-				js.append(", ");
-				js.appendBooleanString(QVTiCGUtil.getAST(cgMapping).isIsStrict());
+				if (!isIncremental) {
+					js.append(", ");
+					js.appendBooleanString(QVTiCGUtil.getAST(cgMapping).isIsStrict());
+				}
 				js.append(")\n");
 				js.append("{\n");
 				js.pushIndentation(null);
@@ -1422,6 +1452,11 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 				js.append("public ");
 				js.appendIsRequired(true);
 				js.append(" " + getMappingName(cgMapping) + " newInstance(");
+				if (isIncremental) {
+					js.append("int ");
+					js.append(QVTiGlobalContext.INVOCATION_HASH_CODE_NAME);
+					js.append(", ");
+				}
 				js.appendIsRequired(true);
 				js.append(" ");
 				js.appendClassReference(Object.class);
@@ -1430,9 +1465,12 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 				js.append(" [] values) {\n");
 				js.pushIndentation(null);
 				js.append("return new " + getMappingName(cgMapping) + "(");
-				//				if (isIncremental) {
-				js.append("this, ");
-				//				}
+				js.append("this");
+				if (isIncremental) {
+					js.append(", ");
+					js.append(QVTiGlobalContext.INVOCATION_HASH_CODE_NAME);
+				}
+				js.append(", ");
 				js.append("values);\n");
 				js.popIndentation();
 				js.append("}\n");
@@ -1442,6 +1480,109 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		}
 	}
 
+	protected void doMappingDestroy(@NonNull CGMapping cgMapping) {
+		js.append("/*\n");
+		js.append(" * Eliminate all trace of the construction and execution of this invocation.\n");
+		js.append(" */\n");
+		js.append("@Override\n");
+		js.append("public synchronized void destroy() {\n");
+		js.pushIndentation(null);
+		js.append("/*\n");
+		js.append(" * Remove this invocation from the invocation cache.\n");
+		js.append(" * Revoke all object property assignments.\n");
+		js.append(" * Revoke all consumed input objects.\n");
+		js.append(" */\n");
+		js.append("super.destroy();\n");
+		/*		Iterable<@NonNull CGGuardVariable> ownedGuardVariables = QVTiCGUtil.getOwnedGuardVariables(cgMapping);
+		if (!Iterables.isEmpty(ownedGuardVariables)) {
+			boolean firstConsume = true;
+			int i = 0;
+			for (@NonNull CGGuardVariable cgGuardVariable : ownedGuardVariables) {
+				if (!(cgGuardVariable instanceof CGConnectionVariable)) {
+					if (firstConsume) {
+						js.append("/*\n");
+						js.append(" * Revoke all consumed input objects.\n");
+						js.append(" * /\n");
+						js.appendClassReference(List.class, Connection.Incremental.class);
+						js.append(" consumedConnections = ");
+						js.append(QVTiGlobalContext.CONSTRUCTOR_NAME);
+						js.append(".getConsumedConnections();\n");
+						firstConsume = false;
+					}
+					js.append("consumedConnections.get(" + i++ + ").revokeConsumer(");
+					js.appendValueName(cgGuardVariable);
+					js.append(", this);\n");
+				}
+			}
+		} */
+		boolean firstAppend = true;
+		for (@NonNull EObject eObject : new TreeIterable(cgMapping, false)) {
+			if (eObject instanceof CGConnectionAssignment) {
+				if (firstAppend) {
+					js.append("/*\n");
+					js.append(" * Revoke all appended output objects.\n");
+					js.append(" */\n");
+					firstAppend = false;
+				}
+				CGConnectionAssignment cgConnectionAssignment = (CGConnectionAssignment)eObject;
+				js.append("if (this.");
+				js.appendValueName(cgConnectionAssignment);
+				js.append(" != null) {\n");
+				js.pushIndentation(null);
+				js.append("this.");
+				js.appendValueName(cgConnectionAssignment.getConnectionVariable());
+				js.append(".revoke(");
+				js.appendValueName(cgConnectionAssignment);
+				js.append(");\n");
+				js.append("this.");
+				js.appendValueName(cgConnectionAssignment);
+				js.append(" = null;\n");
+				js.popIndentation();
+				js.append("}\n");
+			}
+		}
+		Iterable<@NonNull CGRealizedVariable> ownedRealizedVariables = QVTiCGUtil.getOwnedRealizedVariables(cgMapping);
+		if (!Iterables.isEmpty(ownedRealizedVariables)) {
+			js.append("/*\n");
+			js.append(" * Destroy all created objects.\n");
+			js.append(" */\n");
+			for (@NonNull CGRealizedVariable cgRealizedVariable : ownedRealizedVariables) {
+				CGTypedModel cgTypedModel = cgRealizedVariable.getTypedModel();
+				//
+				js.appendClassReference(null, cgRealizedVariable);
+				js.append(" ");
+				js.appendValueName(cgRealizedVariable);
+				js.append(" = this.");
+				js.appendValueName(cgRealizedVariable);
+				js.append(";\n");
+				js.append("if (");
+				js.appendValueName(cgRealizedVariable);
+				js.append(" != null) {\n");
+				js.pushIndentation(null);
+				js.append("((");
+				js.appendClassReference(Model.Incremental.class);
+				js.append(")");
+				js.append(QVTiGlobalContext.MODELS_NAME);
+				js.append("[");
+				appendModelIndex(cgTypedModel);
+				js.append("]).remove(");
+				js.appendValueName(cgRealizedVariable);
+				js.append(");\n");
+				js.append(QVTiGlobalContext.OBJECT_MANAGER_NAME);
+				js.append(".destroyed(");
+				js.appendValueName(cgRealizedVariable);
+				js.append(");\n");
+				js.append("this.");
+				js.appendValueName(cgRealizedVariable);
+				js.append(" = null;\n");
+				js.popIndentation();
+				js.append("}\n");
+			}
+		}
+		js.popIndentation();
+		js.append("}\n");
+	}
+
 	protected boolean doMappingFields(@NonNull CGMapping cgMapping) {
 		boolean needsNewLine = false;
 		for (@NonNull CGGuardVariable cgVariable : ClassUtil.nullFree(cgMapping.getOwnedGuardVariables())) {
@@ -1462,42 +1603,62 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 				js.append(";\n");
 				needsNewLine = true;
 			}
+			for (@NonNull EObject eObject : new TreeIterable(cgMapping, false)) {
+				if (eObject instanceof CGConnectionAssignment) {
+					CGConnectionAssignment cgConnectionAssignment = (CGConnectionAssignment)eObject;
+					js.append("protected ");
+					js.appendClassReference(false, Object.class);
+					js.append(" ");
+					js.appendValueName(cgConnectionAssignment);
+					js.append(" = null;\n");
+					needsNewLine = true;
+				}
+			}
 		}
 		return needsNewLine;
 	}
 
-	protected void doMappingRevokeInvocation(@NonNull CGMapping cgMapping) {
+	protected void doMappingGetBoundValue(@NonNull CGMapping cgMapping) {
+		Iterable<@NonNull CGGuardVariable> cgGuardVariables = QVTiCGUtil.getOwnedGuardVariables(cgMapping);
+		js.append("/*\n");
+		js.append(" * Return the index'th bound value.\n");
+		js.append(" */\n");
 		js.append("@Override\n");
-		js.append("public void revokeInvocation() {\n");
+		js.append("public ");
+		js.appendIsRequired(true);
+		js.append(" ");
+		js.appendClassReference(Object.class);
+		js.append(" getBoundValue(int index) {\n");
 		js.pushIndentation(null);
-		js.append("super.revokeInvocation();\n");
-		for (@NonNull CGRealizedVariable cgRealizedVariable : QVTiCGUtil.getOwnedRealizedVariables(cgMapping)) {
-			CGTypedModel cgTypedModel = cgRealizedVariable.getTypedModel();
-			//
-			js.appendClassReference(null, cgRealizedVariable);
-			js.append(" ");
-			js.appendValueName(cgRealizedVariable);
-			js.append(" = this.");
-			js.appendValueName(cgRealizedVariable);
+		js.append("switch(index) {\n");
+		js.pushIndentation(null);
+		int i = 0;
+		for (@NonNull CGGuardVariable cgGuardVariable : cgGuardVariables) {
+			String valueName = getValueName(cgGuardVariable);
+			js.append("case " + i++ + ": return ");
+			js.append(valueName);
 			js.append(";\n");
-			js.append("if (");
-			js.appendValueName(cgRealizedVariable);
-			js.append(" != null) {\n");
-			js.pushIndentation(null);
-			js.append("((");
-			js.appendClassReference(Model.Incremental.class);
-			js.append(")");
-			js.append(QVTiGlobalContext.MODELS_NAME);
-			js.append("[");
-			appendModelIndex(cgTypedModel);
-			js.append("]).remove(");
-			js.appendValueName(cgRealizedVariable);
-			js.append(");\n");
-			js.popIndentation();
-			js.append("}\n");
 		}
 		js.popIndentation();
 		js.append("}\n");
+		js.append("throw new ");
+		js.appendClassReference(IllegalArgumentException.class);
+		js.append("();\n");
+		js.popIndentation();
+		js.append("}\n");
+	}
+
+	protected void doMappingGetBoundValues(@NonNull CGMapping cgMapping) {
+		Iterable<@NonNull CGGuardVariable> cgGuardVariables = QVTiCGUtil.getOwnedGuardVariables(cgMapping);
+		js.append("/*\n");
+		js.append(" * Return the number of bound values.\n");
+		js.append(" */\n");
+		js.append("@Override\n");
+		js.append("public int getBoundValues() {\n");
+		js.pushIndentation(null);
+		js.append("return " + Iterables.size(cgGuardVariables) + ";\n");
+		js.popIndentation();
+		js.append("}\n");
 	}
 
 	protected void doOppositeCaches(@NonNull QVTiTransformationAnalysis transformationAnalysis) {
@@ -1825,6 +1986,10 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 		BoxedDescriptor concreteBoxedDescriptor = context.getBoxedDescriptor(concreteElementTypeId);
 		BoxedDescriptor abstractBoxedDescriptor = concreteBoxedDescriptor;
 		if (!(initValue.getASTypeId() instanceof CollectionTypeId)) {
+			if (isIncremental) {
+				js.appendValueName(cgConnectionAssignment);
+				js.append(" = ");
+			}
 			js.appendReferenceTo(cgConnectionAssignment.getConnectionVariable());
 			js.append(".appendElement(");
 			js.appendValueName(initValue);
@@ -2173,16 +2338,22 @@ public class QVTiCG2JavaVisitor extends CG2JavaVisitor<@NonNull QVTiCodeGenerato
 						js.append("\n");
 					}
 					doMappingConstructor(cgMapping);
+					if (isIncremental) {
+						js.append("\n");
+						doMappingDestroy(cgMapping);
+					}
 					js.append("\n");
 					js.append("@Override\n");
 					js.append("public boolean execute() ");
 					doMappingBody(cgMapping, true);
-					js.append("\n");
-					doIsEqual(cgFreeVariables);
-					if (isIncremental && !Iterables.isEmpty(QVTiCGUtil.getOwnedRealizedVariables(cgMapping))) {
+					if (isIncremental) {
 						js.append("\n");
-						doMappingRevokeInvocation(cgMapping);
+						doMappingGetBoundValue(cgMapping);
+						js.append("\n");
+						doMappingGetBoundValues(cgMapping);
 					}
+					js.append("\n");
+					doIsEqual(cgFreeVariables);
 					js.popClassBody(false);
 				}
 				else {
diff --git a/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiGlobalContext.java b/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiGlobalContext.java
index 7f2b8af2a..4ea2ba86e 100644
--- a/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiGlobalContext.java
+++ b/plugins/org.eclipse.qvtd.codegen/src/org/eclipse/qvtd/codegen/qvti/java/QVTiGlobalContext.java
@@ -26,6 +26,8 @@ import org.eclipse.ocl.pivot.Property;
 public class QVTiGlobalContext extends JavaGlobalContext<@NonNull QVTiCodeGenerator>
 {
 	public static final @NonNull String CONSTRUCTOR_NAME = "constructor";
+	public static final @NonNull String INVOCATION_HASH_CODE_NAME = "invocationHashCode";
+	public static final @NonNull String OBJECT_MANAGER_NAME = "objectManager";
 	public static final @NonNull String MODELS_NAME = "models";
 
 	/**
@@ -38,7 +40,9 @@ public class QVTiGlobalContext extends JavaGlobalContext<@NonNull QVTiCodeGenera
 		nameManager.reserveName(JavaConstants.EXECUTOR_NAME, null);
 		nameManager.reserveName(JavaConstants.EVALUATION_CACHE_NAME, null);
 		nameManager.reserveName(CONSTRUCTOR_NAME, null);
+		nameManager.reserveName(INVOCATION_HASH_CODE_NAME, null);
 		nameManager.reserveName(MODELS_NAME, null);
+		nameManager.reserveName(OBJECT_MANAGER_NAME, null);
 	}
 
 	public @NonNull String addOppositeProperty(@NonNull Property pivotProperty) {
diff --git a/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/EvaluationStatus2GraphVisitor.java b/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/EvaluationStatus2GraphVisitor.java
deleted file mode 100644
index 1d3b3af67..000000000
--- a/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/EvaluationStatus2GraphVisitor.java
+++ /dev/null
@@ -1,232 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Willink Transformations and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- * 
- * Contributors:
- *     E.D.Willink - initial API and implementation
- ******************************************************************************/
-package org.eclipse.qvtd.pivot.qvtimperative.evaluation;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import org.eclipse.emf.ecore.EClassifier;
-import org.eclipse.emf.ecore.EDataType;
-import org.eclipse.emf.ecore.EReference;
-import org.eclipse.emf.ecore.EStructuralFeature;
-import org.eclipse.jdt.annotation.NonNull;
-import org.eclipse.jdt.annotation.Nullable;
-import org.eclipse.qvtd.pivot.qvtbase.graphs.GraphBuilder;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.AssociationStatus;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.AttributeStatus;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.ClassStatus;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.ElementStatus;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.EvaluationElement;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.MappingStatus;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.PropertyStatus;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.TransformationStatus;
-import org.eclipse.qvtd.pivot.qvtimperative.evaluationstatus.util.AbstractExtendingEvaluationStatusVisitor;
-
-public class EvaluationStatus2GraphVisitor extends AbstractExtendingEvaluationStatusVisitor<String, GraphBuilder>
-{
-	protected static @NonNull String NULL_PLACEHOLDER = "\"<null>\""; //$NON-NLS-1$
-
-	private Map<AssociationStatus, String> associationId = new HashMap<AssociationStatus, String>();
-	private Map<ClassStatus, String> classId = new HashMap<ClassStatus, String>();
-	private Map<MappingStatus, String> mappingId = new HashMap<MappingStatus, String>();
-//	private Map<String, String> propertyId2associationId = new HashMap<String, String>();
-//	private Map<String, PropertyStatus> associationId2propertyStatus = new HashMap<String, PropertyStatus>();
-	
-	public EvaluationStatus2GraphVisitor(@NonNull GraphBuilder context) {
-		super(context);
-	}
-
-	protected @NonNull String getAssociationColor(@NonNull AssociationStatus associationStatus) {
-		if (associationStatus.isIsInput()) {
-			return associationStatus.isIsOutput() ? "#ccffff" : "#ccff00";
-		}
-		else {
-			return associationStatus.isIsOutput() ? "#cc80ff" : "#cc0000";
-		}
-	}
-	
-	protected @NonNull String getAssociationId(@NonNull AssociationStatus object) {
-		String id = associationId.get(object);
-		if (id == null) {
-			id = "a" + associationId.size()+1;
-			associationId.put(object, id);
-		}
-		return id;
-	}
-
-	protected String getAssociationLabel(@NonNull AssociationStatus associationStatus) {
-		EReference forwardReference = associationStatus.getForwardEReference();
-		EReference oppositeReference = forwardReference.getEOpposite();
-		String firstName = forwardReference.getName();
-		String secondName = oppositeReference.getName();
-		boolean swap = false;
-		if (forwardReference.isMany() != oppositeReference.isMany()) {
-			swap = forwardReference.isMany();
-		}
-		else {
-			swap = firstName.compareTo(secondName) > 0;
-		}
-		return swap ? secondName + " / " + firstName : firstName + " / " + secondName;
-	}
-
-	protected @NonNull String getAttributeId(@NonNull AttributeStatus attributeStatus) {
-		ClassStatus classStatus = attributeStatus.getOwningClassStatus();
-		assert classStatus != null;
-		return getClassId(classStatus) + "-" + attributeStatus.getEFeature().getName();
-	}
-
-	protected @NonNull String getClassColor(@NonNull ClassStatus classStatus) {
-		if (classStatus.isIsInput()) {
-			return classStatus.isIsOutput() ? "#ccffff" : "#ccff00";
-		}
-		else {
-			return classStatus.isIsOutput() ? "#cc80ff" : "#cc0000";
-		}
-	}
-	
-	protected @NonNull String getClassId(@NonNull ClassStatus object) {
-		String id = classId.get(object);
-		if (id == null) {
-			id = object.getType().getName() + "-" + (classId.size() + 1);
-			classId.put(object, id);
-		}
-		return id;
-	}
-
-	protected @NonNull String getMappingId(@NonNull MappingStatus object) {
-		String id = mappingId.get(object);
-		if (id == null) {
-			id = object.getReferredMappingCall().getReferredMapping().getName() + "-" + (mappingId.size() + 1);
-			mappingId.put(object, id);
-		}
-		return id;
-	}
-
-	protected @NonNull String getPropertyId(@NonNull PropertyStatus object) {
-		if (object instanceof AssociationStatus) {
-			return getAssociationId((AssociationStatus) object);
-		}
-		else if (object instanceof AttributeStatus) {
-			return getAttributeId((AttributeStatus)object);
-		}
-		else {
-			throw new UnsupportedOperationException();
-		}
-	}
-
-	@Override
-	public String visiting(@NonNull EvaluationElement visitable) {
-//		append(visitable.getClass().getName());
-		return null;
-	}
-
-	@Override
-	public @Nullable String visitAssociationStatus(@NonNull AssociationStatus object) {
-		String associationId = getAssociationId(object);
-		String fillColor = object.isIsError() ? "#ff0000" : getAssociationColor(object);
-		String label = getAssociationLabel(object);
-		context.appendNode(associationId, "rectangle", fillColor, 30, 100, label);
-		for (ClassStatus classStatus : object.getFromClassStatuses()) {
-			if (classStatus != null) {
-				String classId = getClassId(classStatus);
-				context.appendEdge(classId, associationId, "#339966", "line","diamond", "none");
-			}
-		}
-		for (ClassStatus classStatus : object.getToClassStatuses()) {
-			if (classStatus != null) {
-				String classId = getClassId(classStatus);
-				context.appendEdge(classId, associationId, "#339966", "line","diamond", "none");
-			}
-		}
-		return null;
-	}
-
-	@Override
-	public @Nullable String visitAttributeStatus(@NonNull AttributeStatus object) {
-		ClassStatus classStatus = object.getOwningClassStatus();
-		assert classStatus != null;
-		String classId = getClassId(classStatus);
-		String attributeId = getAttributeId(object);
-		String fillColor = object.isIsError() ? "#ff0000" : getClassColor(classStatus);
-		EStructuralFeature eFeature = object.getEFeature();
-		String label = eFeature.getName();
-		EClassifier type = eFeature.getEType();
-//		if (type instanceof DataType) {
-//			Type behavioralType = ((DataType)type).getBehavioralClass();
-//			if (behavioralType != null) {
-//				type = behavioralType;
-//			}
-//		}
-		if (type instanceof EDataType) {
-			label = label + "\n" + String.valueOf(object.getObject());
-		}
-		context.appendNode(attributeId, "rectangle", fillColor, 30, 50, label);
-		context.appendEdge(classId, attributeId, "#339966", "line","diamond", "none");
-		return null;
-	}
-
-	@Override
-	public @Nullable String visitClassStatus(@NonNull ClassStatus object) {
-		String classId = getClassId(object);
-		context.appendNode(classId, "rectangle", getClassColor(object), 30, 120, classId.replace("-",  "\n"));
-		for (AttributeStatus attributeStatus : object.getOwnedAttributeStatuses()) {
-			attributeStatus.accept(this);
-		}
-		return null;
-	}
-
-	@Override
-	public @Nullable String visitMappingStatus(@NonNull MappingStatus object) {
-		String mappingId = getMappingId(object);
-		context.appendNode(mappingId, "hexagon", "#ffcc00", 30, 150, mappingId.replace("-",  "\n"));
-		for (ElementStatus inputStatus : object.getInputs()) {
-			if (inputStatus instanceof ClassStatus) {
-				ClassStatus classStatus = (ClassStatus)inputStatus;
-				String classId = getClassId(classStatus);
-				context.appendEdge(classId, mappingId, "#000000", "line","none", "standard");
-			}
-			else if (inputStatus instanceof PropertyStatus) {
-				PropertyStatus propertyStatus = (PropertyStatus)inputStatus;
-				String propertyId = getPropertyId(propertyStatus);
-				context.appendEdge(propertyId, mappingId, "#000000", "dashed","none", "standard");
-			}
-		}
-		for (ElementStatus outputStatus : object.getOutputs()) {
-			if (outputStatus instanceof ClassStatus) {
-				ClassStatus classStatus = (ClassStatus)outputStatus;
-				String classId = getClassId(classStatus);
-				context.appendEdge(mappingId, classId, "#000000", "line","none", "standard");
-			}
-			else if (outputStatus instanceof PropertyStatus) {
-				PropertyStatus propertyStatus = (PropertyStatus)outputStatus;
-				String propertyId = getPropertyId(propertyStatus);
-				context.appendEdge(mappingId, propertyId, "#000000", "dashed","none", "standard");
-			}
-		}
-		return null;
-	}
-
-	@Override
-	public @Nullable String visitTransformationStatus(@NonNull TransformationStatus object) {
-		context.open();
-			for (ClassStatus classStatus : object.getOwnedClassStatuses()) {
-				classStatus.accept(this);
-			}
-			for (MappingStatus mappingStatus : object.getOwnedMappingStatuses()) {
-				mappingStatus.accept(this);
-			}
-			for (AssociationStatus associationStatus : object.getOwnedAssociationStatuses()) {
-				associationStatus.accept(this);
-			}
-		context.close();
-		return null;
-	}
-}
diff --git a/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/Execution2GraphVisitor.java b/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/Execution2GraphVisitor.java
index 2879918d1..b13ecb791 100644
--- a/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/Execution2GraphVisitor.java
+++ b/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/Execution2GraphVisitor.java
@@ -220,7 +220,7 @@ public class Execution2GraphVisitor extends AbstractExecutionVisitor<@Nullable O
 				public void appendNode(@NonNull GraphStringBuilder s, @NonNull String nodeName) {
 					s.setLabel(label);
 					s.setShape("ellipse");
-					s.setColor("brown");
+					s.setColor("blue");
 					s.appendAttributedNode(nodeName);
 				}
 			};
@@ -419,7 +419,7 @@ public class Execution2GraphVisitor extends AbstractExecutionVisitor<@Nullable O
 			Object value = object.getValue(i);
 			if (value != null) {
 				GraphNode objectNode = getObjectNode(value);
-				appendEdge(connectionNode, objectNode, "brown", "dotted");
+				appendEdge(connectionNode, objectNode, "blue", "dotted");
 				//			for (@NonNull Invocation invocation : object.getConsumers(i)) {
 				//				GraphNode consumerNode = getInvocationNode(invocation);
 				//			}
@@ -502,8 +502,22 @@ public class Execution2GraphVisitor extends AbstractExecutionVisitor<@Nullable O
 
 	@Override
 	public @Nullable String visitInvocation(@NonNull Invocation object) {
-		@SuppressWarnings("unused")
 		GraphNode invocationNode = getInvocationNode(object);
+		if (object instanceof Invocation.Incremental) {
+			Invocation.Incremental invocation = (Invocation.Incremental)object;
+			int iMax = invocation.getBoundValues();
+			for (int i = 0; i < iMax; i++) {
+				Object boundObject = invocation.getBoundValue(i);
+				if (boundObject instanceof Connection) {
+					GraphNode connectionNode = getConnectionNode((Connection) boundObject);
+					appendEdge(invocationNode, connectionNode, "green", "dotted");
+				}
+				else {
+					GraphNode objectNode = getObjectNode(boundObject);
+					appendEdge(objectNode, invocationNode, "cyan", null);
+				}
+			}
+		}
 		/*		context.appendNode(mappingId, "hexagon", "#ffcc00", 30, 150, mappingId.replace("-",  "\n"));
 			for (ElementStatus inputStatus : object.getInputs()) {
 				if (inputStatus instanceof ClassStatus) {
@@ -537,7 +551,7 @@ public class Execution2GraphVisitor extends AbstractExecutionVisitor<@Nullable O
 		GraphNode invokerNode = getInvocationConstructorNode(object);
 		GraphNode intervalNode = getIntervalNode(object.getInterval());
 		appendEdge(invokerNode, intervalNode, "black", "dashed");
-		for (@NonNull Invocation invocation : object.getInvocations()) {
+		for (@NonNull Invocation invocation : object.debugGetInvocations()) {
 			GraphNode invocationNode = getInvocationNode(invocation);
 			appendEdge(invokerNode, invocationNode, "orange", "dotted");
 		}
@@ -593,10 +607,10 @@ public class Execution2GraphVisitor extends AbstractExecutionVisitor<@Nullable O
 			GraphNode slotNode = getSlotNode(slotState);
 			slotState.accept(this);
 			for (@NonNull Invocation invocation : slotState.getSources()) {
-				appendEdge(getInvocationNode(invocation), slotNode, "green", null);
+				appendEdge(getInvocationNode(invocation), slotNode, "green", "dashed");
 			}
 			for (@NonNull Execution invocation : slotState.getTargets()) {
-				appendEdge(slotNode, getExecutionNode(invocation), "cyan", null);
+				appendEdge(slotNode, getExecutionNode(invocation), "cyan", "dashed");
 			}
 			Iterables.addAll(allExecutions, slotState.getTargets());
 		}
@@ -607,7 +621,7 @@ public class Execution2GraphVisitor extends AbstractExecutionVisitor<@Nullable O
 				for (SlotState.@NonNull Incremental slotState : slots) {
 					GraphNode slotNode = getSlotNode(slotState);
 					slotState.accept(this);
-					appendEdge(objectNode, slotNode, "blue", null);
+					appendEdge(objectNode, slotNode, "blue", "dashed");
 				}
 			}
 		}
diff --git a/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/QVTiIncrementalExecutor.java b/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/QVTiIncrementalExecutor.java
index c8227f3d1..3abc70689 100644
--- a/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/QVTiIncrementalExecutor.java
+++ b/plugins/org.eclipse.qvtd.pivot.qvtimperative/src/org/eclipse/qvtd/pivot/qvtimperative/evaluation/QVTiIncrementalExecutor.java
@@ -77,15 +77,15 @@ public class QVTiIncrementalExecutor extends BasicQVTiExecutor
 
 		public InterpretedInvocationConstructor(@NonNull QVTiIncrementalExecutor executor, @NonNull Mapping asMapping,
 				@NonNull MappingCall mappingCall, @NonNull EvaluationVisitor undecoratedVisitor) {
-			super(executor.getInvocationManager(), QVTimperativeUtil.getName(asMapping), asMapping.isIsStrict());
+			super(executor.getInvocationManager(), QVTimperativeUtil.getName(asMapping));
 			this.executor = executor;
 			this.mappingCall = mappingCall;
 			this.undecoratedVisitor = undecoratedVisitor;
 		}
 
 		@Override
-		public @NonNull Invocation newInstance(@NonNull Object @NonNull [] theseValues) {
-			return new InterpretedInvocation(this, theseValues);
+		public @NonNull Invocation newInstance(int invocationHashCode, @NonNull Object @NonNull [] theseValues) {
+			return new InterpretedInvocation(this, invocationHashCode, theseValues);
 		}
 
 		private Object internalExecuteInvocation(@NonNull InterpretedInvocation invocation, @NonNull Object @NonNull [] theseValues) {
@@ -97,8 +97,8 @@ public class QVTiIncrementalExecutor extends BasicQVTiExecutor
 	{
 		protected final @NonNull Object @NonNull [] theseValues;
 
-		public InterpretedInvocation(@NonNull InterpretedInvocationConstructor constructor, @NonNull Object @NonNull [] theseValues) {
-			super(constructor);
+		public InterpretedInvocation(@NonNull InterpretedInvocationConstructor constructor, int invocationHashCode, @NonNull Object @NonNull [] theseValues) {
+			super(constructor, invocationHashCode);
 			int iMax = theseValues.length;
 			this.theseValues = new @NonNull Object[iMax];
 			for (int i = 0; i < iMax; i++) {
@@ -113,6 +113,16 @@ public class QVTiIncrementalExecutor extends BasicQVTiExecutor
 		}
 
 		@Override
+		public @NonNull Object getBoundValue(int index) {
+			return theseValues[index];
+		}
+
+		@Override
+		public int getBoundValues() {
+			return theseValues.length;
+		}
+
+		@Override
 		public boolean isEqual(@NonNull IdResolver idResolver, @NonNull Object @NonNull [] thoseValues) {
 			int iMax = thoseValues.length;
 			if (iMax != theseValues.length) {
@@ -192,7 +202,7 @@ public class QVTiIncrementalExecutor extends BasicQVTiExecutor
 			{
 				@Override
 				public @NonNull Computation newInstance(@Nullable Object @NonNull [] theseValues) {
-					Computation.Incremental computation = new AbstractComputation.Incremental()
+					Computation.Incremental computation = new AbstractComputation.Incremental(PivotUtil.getName(asFunction))
 					{
 						protected Object result = QVTiIncrementalExecutor.super.internalExecuteFunctionCallExp(operationCallExp, asFunction, theseValues);
 
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractComputation.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractComputation.java
index eb3395025..47bf86b56 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractComputation.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractComputation.java
@@ -26,8 +26,13 @@ public abstract class AbstractComputation implements Computation
 	{
 		public static final @NonNull List<@NonNull Object> EMPTY_OBJECT_LIST = Collections.emptyList();
 
+		protected final @NonNull String name;
 		private Set<SlotState.@NonNull Incremental> readSlots = null;
 
+		protected Incremental(@NonNull String name) {
+			this.name = name;
+		}
+
 		@Override
 		public void addReadSlot(SlotState.@NonNull Incremental readSlot) {
 			if (readSlots == null) {
@@ -43,13 +48,18 @@ public abstract class AbstractComputation implements Computation
 		}
 
 		@Override
-		public void revokeExecution() {
+		public void destroy() {
 			// TODO Auto-generated method stub
 
 		}
 
 		@Override
-		public void revokeInvocation() {
+		public @NonNull String getName() {
+			return name;
+		}
+
+		@Override
+		public void revoke() {
 			// TODO Auto-generated method stub
 
 		}
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractInvocation.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractInvocation.java
index 307f916d7..70ba1c3ce 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractInvocation.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractInvocation.java
@@ -17,6 +17,7 @@ import java.util.Set;
 
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.ocl.pivot.ids.TypeId;
+import org.eclipse.qvtd.runtime.internal.evaluation.AbstractIntervalInternal;
 import org.eclipse.qvtd.runtime.internal.evaluation.AbstractInvocationInternal;
 
 /**
@@ -29,16 +30,19 @@ public abstract class AbstractInvocation extends AbstractInvocationInternal
 		public static final @NonNull List<@NonNull Object> EMPTY_OBJECT_LIST = Collections.emptyList();
 		public static final @NonNull List<SlotState.@NonNull Incremental> EMPTY_SLOT_LIST = Collections.emptyList();
 
-		protected final @NonNull InvocationConstructor constructor;
+		protected final InvocationConstructor.@NonNull Incremental constructor;
+		private final int invocationHashCode;
 		protected final int sequence;
 
 		private Set<@NonNull Object> createdObjects = null;
 		private Set<SlotState.@NonNull Incremental> readSlots = null;
 		private Set<SlotState.@NonNull Incremental> writeSlots = null;
+		private boolean isDestroyed = false;
 
-		protected Incremental(InvocationConstructor.@NonNull Incremental constructor) {
+		protected Incremental(InvocationConstructor.@NonNull Incremental constructor, int invocationHashCode) {
 			super(constructor);
 			this.constructor = constructor;
+			this.invocationHashCode = invocationHashCode;
 			this.sequence = constructor.nextSequence();
 		}
 
@@ -77,6 +81,33 @@ public abstract class AbstractInvocation extends AbstractInvocationInternal
 		}
 
 		@Override
+		public void destroy() {
+			isDestroyed = true;
+			((AbstractIntervalInternal)interval).destroy(this);
+			constructor.destroy(this, invocationHashCode);
+			if (AbstractTransformer.INVOCATIONS.isActive()) {
+				AbstractTransformer.INVOCATIONS.println("destroy " + this);
+			}
+			if (writeSlots != null) {
+				for (SlotState.@NonNull Incremental writeSlot : writeSlots) {
+					writeSlot.revokeAssigned();
+				}
+			}
+			/*
+			 * Revoke all consumed input objects.
+			 */
+			int i = 0;
+			for (Connection.@NonNull Incremental consumedConnection : constructor.getConsumedConnections()) {
+				consumedConnection.revokeConsumer(getBoundValue(i), this);
+			}
+		}
+
+		@Override
+		public InvocationConstructor.@NonNull Incremental getConstructor() {
+			return constructor;
+		}
+
+		@Override
 		public @NonNull Iterable<@NonNull Object> getCreatedObjects() {
 			return createdObjects != null ? createdObjects : EMPTY_OBJECT_LIST;
 		}
@@ -99,29 +130,29 @@ public abstract class AbstractInvocation extends AbstractInvocationInternal
 		}
 
 		@Override
-		public void revokeExecution() {
-			if (writeSlots != null) {
-				for (SlotState.@NonNull Incremental writeSlot : writeSlots) {
-					writeSlot.revokeAssigned();
-				}
+		public void revoke() {
+			if (AbstractTransformer.INVOCATIONS.isActive()) {
+				AbstractTransformer.INVOCATIONS.println("revoke " + this);
 			}
-			interval.queue(this);
-		}
-
-		@Override
-		public void revokeInvocation() {
 			if (writeSlots != null) {
 				for (SlotState.@NonNull Incremental writeSlot : writeSlots) {
 					writeSlot.revokeAssigned();
 				}
 			}
-			interval.queue(this);
+			if (!isDestroyed) {
+				interval.queue(this);
+			}
 		}
 
 		@Override
 		public @NonNull String toString() {
 			return getName();
 		}
+
+		@Override
+		public void unblock() {
+			super.unblock();
+		}
 	}
 
 	protected AbstractInvocation(@NonNull InvocationConstructor constructor) {
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractSlotState.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractSlotState.java
index 8668c73e1..c58d4d5bc 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractSlotState.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/AbstractSlotState.java
@@ -61,7 +61,7 @@ public abstract class AbstractSlotState implements SlotState
 
 		protected void revokeTargets() {
 			for (Execution.@NonNull Incremental target : getTargets()) {
-				target.revokeExecution();
+				target.revoke();
 			}
 		}
 	}
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Connection.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Connection.java
index 2133f0555..1484228bc 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Connection.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Connection.java
@@ -70,6 +70,8 @@ public interface Connection extends ExecutionVisitable, Nameable
 		 * so that their appends are also revoked.
 		 */
 		void revoke(@NonNull Object connectionKey);
+
+		void revokeConsumer(@NonNull Object anElement, Invocation.@NonNull Incremental invocation);
 	}
 
 	void addAppender(@NonNull InvocationConstructor appendingInvoker);
@@ -84,6 +86,8 @@ public interface Connection extends ExecutionVisitable, Nameable
 	 */
 	@NonNull Object appendElement(@NonNull Object anElement);
 
+	int debugGetSize();
+
 	int getCapacity();
 
 	@NonNull Iterable<@NonNull InvocationConstructor> getConsumers();
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Execution.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Execution.java
index 4263778af..84c21d068 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Execution.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Execution.java
@@ -30,13 +30,13 @@ public interface Execution extends ExecutionVisitable, Nameable
 		 * Revoke the consequences of a previous execution in preparation for a new execution.
 		 * This reverts all assigned slot states back to REASSIGNABLE.
 		 */
-		void revokeExecution();
+		void revoke();
 
 		/**
 		 * Revoke the consequences of a previous execution that will not be re-executed.
 		 * All created objects are revoked.
 		 */
-		void revokeInvocation();
+		void destroy();
 	}
 
 	@Override
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Invocation.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Invocation.java
index aad465730..a99b73c6f 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Invocation.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Invocation.java
@@ -49,8 +49,10 @@ public interface Invocation extends Execution
 	{
 		void addCreatedObject(@NonNull Object createdObject);
 		void addWriteSlot(SlotState.@NonNull Incremental writeSlot);
+		@NonNull Object getBoundValue(int index);
+		int getBoundValues();
+		InvocationConstructor.@NonNull Incremental getConstructor();
 		@NonNull Iterable<SlotState.@NonNull Incremental> getReadSlots();
 		@NonNull Iterable<SlotState.@NonNull Incremental> getWriteSlots();
-		//		void invalidate();
 	}
 }
\ No newline at end of file
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/InvocationConstructor.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/InvocationConstructor.java
index 55a96ecd7..e1d27625b 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/InvocationConstructor.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/InvocationConstructor.java
@@ -10,6 +10,8 @@
  *******************************************************************************/
 package org.eclipse.qvtd.runtime.evaluation;
 
+import java.util.List;
+
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.ocl.pivot.utilities.Nameable;
 
@@ -22,6 +24,11 @@ public interface InvocationConstructor extends ExecutionVisitable, Nameable
 {
 	public interface Incremental extends InvocationConstructor
 	{
+		void addConsumedConnection(Connection.@NonNull Incremental connection);
+
+		void destroy(AbstractInvocation.@NonNull Incremental incremental, int invocationHashCode);
+
+		@NonNull List<Connection.@NonNull Incremental> getConsumedConnections();
 
 		int nextSequence();
 	}
@@ -30,9 +37,9 @@ public interface InvocationConstructor extends ExecutionVisitable, Nameable
 
 	void addConsumedConnection(@NonNull Connection connection);
 
-	@NonNull Interval getInterval();
+	@NonNull Iterable<@NonNull Invocation> debugGetInvocations();
 
-	@NonNull Iterable<@NonNull Invocation> getInvocations();
+	@NonNull Interval getInterval();
 
 	@Override
 	@NonNull String getName();
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/ObjectManager.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/ObjectManager.java
index b23adb716..1dfcbe3d3 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/ObjectManager.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/ObjectManager.java
@@ -40,6 +40,8 @@ public interface ObjectManager extends ExecutionVisitable
 	 */
 	void created(Invocation.@NonNull Incremental invocation, @NonNull Object eObject);
 
+	void destroyed(@NonNull Object eObject);
+
 	@NonNull Iterable<@NonNull ? extends Object> getObjects();
 	@NonNull Iterable<@NonNull ? extends SlotState> getSlotStates(@NonNull Object object);
 
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/StrictIncrementalConnection.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/StrictIncrementalConnection.java
index ca62a88c9..7339e8942 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/StrictIncrementalConnection.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/StrictIncrementalConnection.java
@@ -45,9 +45,9 @@ public class StrictIncrementalConnection extends StrictIncrementalConnectionInte
 				if (count <= 0) {
 					listOfValueAndConsumingInvocations.set(i, null);
 					int jMax = valueAndConsumingInvocations.size();
-					for (int j = INDEX_INDEX+1; j < jMax; j++) {
+					for (int j = COUNT_INDEX+1; j < jMax; j++) {
 						AbstractInvocation.Incremental consumingInvocation = (AbstractInvocation.Incremental) valueAndConsumingInvocations.get(j);
-						consumingInvocation.revokeExecution();
+						consumingInvocation.revoke();
 					}
 				}
 				else {
@@ -57,4 +57,22 @@ public class StrictIncrementalConnection extends StrictIncrementalConnectionInte
 			}
 		}
 	}
+
+	@Override
+	public void revokeConsumer(@NonNull Object anElement, Invocation.@NonNull Incremental invocation) {	// FIXME Use connectionKey
+		for (int i = 0; i < listOfValueAndConsumingInvocations.size(); i++) {
+			List<@NonNull Object> valueAndConsumingInvocations = listOfValueAndConsumingInvocations.get(i);
+			if ((valueAndConsumingInvocations != null) && (valueAndConsumingInvocations.get(VALUE_INDEX) == anElement)) {
+				int jMax = valueAndConsumingInvocations.size();
+				for (int j = COUNT_INDEX+1; j < jMax; j++) {
+					AbstractInvocation.Incremental consumingInvocation = (AbstractInvocation.Incremental) valueAndConsumingInvocations.get(j);
+					if (consumingInvocation == invocation) {
+						valueAndConsumingInvocations.remove(j);
+						break;
+					}
+				}
+				break;
+			}
+		}
+	}
 }
\ No newline at end of file
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Transformer.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Transformer.java
index 0a56a9c0b..57c0b7a6d 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Transformer.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/evaluation/Transformer.java
@@ -48,5 +48,6 @@ public interface Transformer extends ExecutionVisitable
 	@NonNull ObjectManager getObjectManager();
 	@NonNull Collection<@NonNull ? extends EObject> getRootEObjects(@NonNull String modelName);
 	@NonNull Collection<@NonNull Object> getRootObjects(@NonNull String modelName);
+	@NonNull TypedModelInstance getTypedModelInstance(@NonNull String modelName);
 	boolean run() throws Exception;
 }
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractConnectionInternal.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractConnectionInternal.java
index 514c509e8..3f42278e7 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractConnectionInternal.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractConnectionInternal.java
@@ -59,6 +59,11 @@ public abstract class AbstractConnectionInternal extends AbstractConnection
 	}
 
 	@Override
+	public int debugGetSize() {
+		return values.size();
+	}
+
+	@Override
 	public int getCapacity() {
 		return values.size();
 	}
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIncrementalConnectionInternal.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIncrementalConnectionInternal.java
index 6b8c13363..7b00eb9e4 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIncrementalConnectionInternal.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIncrementalConnectionInternal.java
@@ -148,6 +148,17 @@ public abstract class AbstractIncrementalConnectionInternal extends AbstractConn
 	}
 
 	@Override
+	public int debugGetSize() {
+		int size = 0;
+		for (@Nullable List<@NonNull Object> valueAndConsumingInvocations : listOfValueAndConsumingInvocations) {
+			if (valueAndConsumingInvocations != null) {
+				size++;
+			}
+		}
+		return size;
+	}
+
+	@Override
 	public @NonNull Iterable<@NonNull InvocationConstructor> getAppenders() {
 		return appenders;
 	}
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIntervalInternal.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIntervalInternal.java
index b87f37981..98b3b6c18 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIntervalInternal.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractIntervalInternal.java
@@ -125,6 +125,29 @@ public abstract class AbstractIntervalInternal implements Interval
 		return connection;
 	}
 
+	public synchronized void destroy(@NonNull Invocation invocation) {
+		assert invocation.getInterval() == this;
+		if (debugInvocations) {
+			AbstractTransformer.INVOCATIONS.println("destroy " + invocation);
+		}
+		AbstractInvocationInternal castInvocation = (AbstractInvocationInternal) invocation;
+		assert blockedInvocations != castInvocation;
+		if (waitingInvocations == castInvocation) {
+			waitingInvocations = castInvocation.next;
+			if (waitingInvocations == castInvocation) {
+				waitingInvocations = null;
+			}
+		}
+		AbstractInvocationInternal prevInvocation = castInvocation.prev;
+		if (prevInvocation != castInvocation) {
+			AbstractInvocationInternal nextInvocation = castInvocation.next;
+			prevInvocation.next = nextInvocation;
+			nextInvocation.prev = prevInvocation;
+			castInvocation.next = castInvocation;
+			castInvocation.prev = castInvocation;
+		}
+	}
+
 	@Override
 	public boolean flush() {
 		while (headConnection != null) {
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationConstructor.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationConstructor.java
index 8bbfe1d18..a8922812b 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationConstructor.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationConstructor.java
@@ -14,11 +14,11 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.ocl.pivot.evaluation.Executor;
 import org.eclipse.ocl.pivot.ids.IdResolver;
+import org.eclipse.qvtd.runtime.evaluation.AbstractInvocation;
 import org.eclipse.qvtd.runtime.evaluation.Connection;
 import org.eclipse.qvtd.runtime.evaluation.ExecutionVisitor;
 import org.eclipse.qvtd.runtime.evaluation.Interval;
@@ -32,8 +32,30 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 	{
 		protected int sequence = 0;
 
-		public Incremental(@NonNull InvocationManager invocationManager, @NonNull String name, boolean isStrict) {
-			super(invocationManager, name, isStrict);
+		/**
+		 * List of consumed connections.
+		 */
+		private final @NonNull List<Connection.@NonNull Incremental> consumedConnections = new ArrayList<>();
+
+		public Incremental(@NonNull InvocationManager invocationManager, @NonNull String name) {
+			super(invocationManager, name, true);
+		}
+
+		@Override
+		public synchronized void addConsumedConnection(Connection.@NonNull Incremental connection) {
+			//			assert !consumedConnections.contains(connection);
+			consumedConnections.add(connection);
+			super.addConsumedConnection(connection);
+		}
+
+		@Override
+		public @NonNull List<Connection.@NonNull Incremental> getConsumedConnections() {
+			return consumedConnections;
+		}
+
+		@Override
+		protected final @NonNull Invocation newInstance(@NonNull Object @NonNull [] values) {
+			throw new IllegalStateException("Incremental invocations require an invocationHashCode.");
 		}
 
 		@Override
@@ -254,7 +276,7 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 	/**
 	 * Flattened copy of hashCode2invocations.values(). Not maintained until actually requested.
 	 */
-	private /*@LazyNonNull*/ List<@NonNull Invocation> allInvocations = null;
+	//	private /*@LazyNonNull*/ List<@NonNull Invocation> allInvocations = null;
 
 	/**
 	 * The number of values required to match the Mapping.ownedParameters.
@@ -319,8 +341,6 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 	@Override
 	public synchronized void addConsumedConnection(@NonNull Connection connection) {
 		assert values == null;
-		//		assert !consumedConnections.contains(connection);
-		//		consumedConnections.add(connection);
 		connection.addConsumer(this);
 		if (firstConsumer != null) {
 			firstConsumer.appendConsumer(valuesCount, connection);
@@ -332,27 +352,42 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 		valuesCount++;
 	}
 
+	//	@Override
+	public synchronized void destroy(AbstractInvocation.@NonNull Incremental invocation, int invocationHashCode) {
+		Object zeroOrMoreInvocations = hashCode2invocations.get(invocationHashCode);
+		if (zeroOrMoreInvocations instanceof Invocation) {
+			Invocation oneInvocation = (Invocation)zeroOrMoreInvocations;
+			if (oneInvocation == invocation) {
+				hashCode2invocations.remove(invocationHashCode);
+			}
+		}
+		else if (zeroOrMoreInvocations instanceof List<?>) {
+			@SuppressWarnings("unchecked")@NonNull List<@NonNull Invocation> zeroOrMoreInvocations2 = (List<@NonNull Invocation>)zeroOrMoreInvocations;
+			zeroOrMoreInvocations2.remove(invocation);
+			if (zeroOrMoreInvocations2.size() == 1) {
+				hashCode2invocations.put(invocationHashCode, zeroOrMoreInvocations2.get(0));
+			}
+		}
+	}
+
 	@Override
 	public @NonNull Interval getInterval() {
 		return interval;
 	}
 
 	@Override
-	public @NonNull Iterable<@NonNull Invocation> getInvocations() {
-		List<@NonNull Invocation> allInvocations2 = allInvocations;
-		if (allInvocations2 == null) {
-			allInvocations2 = allInvocations = new ArrayList<>();
-			for (Object zeroOrMoreInvocations : hashCode2invocations.values()) {
-				if (zeroOrMoreInvocations instanceof Invocation) {
-					allInvocations2.add((Invocation)zeroOrMoreInvocations);
-				}
-				else if (zeroOrMoreInvocations instanceof List<?>) {
-					@SuppressWarnings("unchecked")@NonNull List<@NonNull Invocation> zeroOrMoreInvocations2 = (List<@NonNull Invocation>)zeroOrMoreInvocations;
-					allInvocations2.addAll(zeroOrMoreInvocations2);
-				}
+	public @NonNull Iterable<@NonNull Invocation> debugGetInvocations() {
+		List<@NonNull Invocation> allInvocations = new ArrayList<>();
+		for (Object zeroOrMoreInvocations : hashCode2invocations.values()) {
+			if (zeroOrMoreInvocations instanceof Invocation) {
+				allInvocations.add((Invocation)zeroOrMoreInvocations);
+			}
+			else if (zeroOrMoreInvocations instanceof List<?>) {
+				@SuppressWarnings("unchecked")@NonNull List<@NonNull Invocation> zeroOrMoreInvocations2 = (List<@NonNull Invocation>)zeroOrMoreInvocations;
+				allInvocations.addAll(zeroOrMoreInvocations2);
 			}
 		}
-		return allInvocations2;
+		return allInvocations;
 	}
 
 	@Override
@@ -368,12 +403,12 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 	public @NonNull Invocation invoke(@NonNull Object @NonNull ... argValues) {
 		Invocation theInvocation;
 		if (isStrict) {
-			int hashCode = 0;
-			for (@Nullable Object argValue : argValues) {
-				hashCode = 3 * hashCode + idResolver.oclHashCode(argValue);
+			int invocationHashCode = 0;
+			for (@NonNull Object argValue : argValues) {
+				invocationHashCode = 3 * invocationHashCode + idResolver.oclHashCode(argValue);
 			}
 			synchronized (hashCode2invocations) {
-				Object zeroOrMoreInvocations = hashCode2invocations.get(hashCode);
+				Object zeroOrMoreInvocations = hashCode2invocations.get(invocationHashCode);
 				Invocation oneInvocation = null;
 				List<@NonNull Invocation> twoOrMoreInvocations = null;
 				if (zeroOrMoreInvocations instanceof Invocation) {
@@ -391,16 +426,16 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 						}
 					}
 				}
-				theInvocation = newInstance(argValues);
+				theInvocation = newInstance(invocationHashCode, argValues);
 				if (zeroOrMoreInvocations == null) {
-					hashCode2invocations.put(hashCode, theInvocation);
+					hashCode2invocations.put(invocationHashCode, theInvocation);
 				}
 				else if (twoOrMoreInvocations == null) {
 					twoOrMoreInvocations = new ArrayList<@NonNull Invocation>(4);
 					assert oneInvocation != null;
 					twoOrMoreInvocations.add(oneInvocation);
 					twoOrMoreInvocations.add(theInvocation);
-					hashCode2invocations.put(hashCode, twoOrMoreInvocations);
+					hashCode2invocations.put(invocationHashCode, twoOrMoreInvocations);
 				}
 				else {
 					twoOrMoreInvocations.add(theInvocation);
@@ -410,9 +445,9 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 		else {
 			theInvocation = newInstance(argValues);
 		}
-		if (allInvocations != null) {
-			allInvocations.add(theInvocation);
-		}
+		//		if (allInvocations != null) {
+		//			allInvocations.add(theInvocation);
+		//		}
 		interval.queue(theInvocation);
 		return theInvocation;
 	}
@@ -433,6 +468,14 @@ public abstract class AbstractInvocationConstructor implements InvocationConstru
 	 */
 	protected abstract @NonNull Invocation newInstance(@NonNull Object @NonNull [] values);
 
+	/**
+	 * Create the mapping instance. In due course, its execute() method is invoked.
+	 * Eventually the invocationHashCode may be used to facilitate destroy().
+	 */
+	protected @NonNull Invocation newInstance(int invocationHashCode, @NonNull Object @NonNull [] values) {
+		return newInstance(values);
+	}
+
 	@Override
 	public void propagate() {
 		@NonNull Object[] values2 = values;
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationManagerInternal.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationManagerInternal.java
index 127591bba..1a4730ac1 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationManagerInternal.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractInvocationManagerInternal.java
@@ -18,8 +18,11 @@ import org.eclipse.ocl.pivot.evaluation.Executor;
 import org.eclipse.qvtd.runtime.evaluation.AbstractInvocationManager;
 import org.eclipse.qvtd.runtime.evaluation.DefaultInterval;
 import org.eclipse.qvtd.runtime.evaluation.Interval;
+import org.eclipse.qvtd.runtime.evaluation.Invocation;
 import org.eclipse.qvtd.runtime.evaluation.InvocationConstructor;
 
+import com.google.common.collect.Iterables;
+
 /**
  * InvocationManager supervises and provides thread safety for the lists of blocked and waiting invocations.
  */
@@ -70,6 +73,14 @@ public abstract class AbstractInvocationManagerInternal extends AbstractInvocati
 		return invoker;
 	} */
 
+	public @NonNull Iterable<@NonNull Invocation> debugGetAllInvocations() {
+		List<@NonNull Invocation> allInvocations = new ArrayList<>();
+		for (@NonNull InvocationConstructor invoker : invokers) {
+			Iterables.addAll(allInvocations, invoker.debugGetInvocations());
+		}
+		return allInvocations;
+	}
+
 	@Override
 	public boolean flush() {
 		for (int index = nextIndex; index < intervals.size(); index = nextIndex) {
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractTransformerInternal.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractTransformerInternal.java
index a405199f0..2cded70b5 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractTransformerInternal.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/AbstractTransformerInternal.java
@@ -123,7 +123,8 @@ public abstract class AbstractTransformerInternal /*extends AbstractModelManager
 					Set<@NonNull Integer> allClassIndexes = eClass2allClassIndexes.get(eClass);
 					if (allClassIndexes != null) {
 						for (@NonNull Integer classIndex : allClassIndexes) {
-							((Connection.Incremental)classIndex2connection[classIndex]).removeElement(eObject);
+							Connection.Incremental connection = (Connection.Incremental)classIndex2connection[classIndex];
+							connection.removeElement(eObject);
 						}
 					}
 				}
@@ -190,7 +191,7 @@ public abstract class AbstractTransformerInternal /*extends AbstractModelManager
 			for (int i = 0; i < classIds; i++) {
 				@NonNull
 				ClassId classId = classIndex2classId[i];
-				classIndex2connection[i] = transformer.createConnection(name + "-" + classId, classId, false);
+				classIndex2connection[i] = transformer.createConnection(name /*+ "-" + classId*/, classId, false);
 			}
 		}
 
@@ -266,9 +267,9 @@ public abstract class AbstractTransformerInternal /*extends AbstractModelManager
 				isNotContainedCount++;
 				assert !potentialOrphanObjects.contains(eObject);
 				potentialOrphanObjects.add(eObject);
-				EClass eClass = transformer.eClass(eObject);
-				accumulateEObject1(eObject, eClass);
 			}
+			EClass eClass = transformer.eClass(eObject);
+			accumulateEObject1(eObject, eClass);
 		}
 
 		/**
@@ -580,11 +581,7 @@ public abstract class AbstractTransformerInternal /*extends AbstractModelManager
 	 */
 	@Override
 	public void addRootObjects(@NonNull String modelName, @NonNull Iterable<@NonNull ? extends Object> eRootObjects) {
-		Integer modelIndex = modelIndexes.get(modelName);
-		if (modelIndex == null) {
-			throw new IllegalStateException("Unknown model name '" + modelName + "'");
-		}
-		models[modelIndex].addRootObjects(eRootObjects);
+		getTypedModelInstance(modelName).addRootObjects(eRootObjects);
 	}
 
 	protected @NonNull Connection createConnection(@NonNull String name, @NonNull TypeId typeId, boolean isStrict) {
@@ -740,12 +737,9 @@ public abstract class AbstractTransformerInternal /*extends AbstractModelManager
 	 */
 	@Override
 	public @NonNull Collection<@NonNull EObject> getRootEObjects(@NonNull String modelName) {
-		Integer modelIndex = modelIndexes.get(modelName);
-		if (modelIndex == null) {
-			throw new IllegalStateException("Unknown model name '" + modelName + "'");
-		}
+		Model model = getTypedModelInstance(modelName);
 		List<@NonNull EObject> rootEObjects = new ArrayList<>();
-		for (@NonNull Object rootObject : models[modelIndex].getRootObjects()) {
+		for (@NonNull Object rootObject : model.getRootObjects()) {
 			if (rootObject instanceof EObject) {
 				rootEObjects.add((EObject)rootObject);
 			}
@@ -758,11 +752,16 @@ public abstract class AbstractTransformerInternal /*extends AbstractModelManager
 	 */
 	@Override
 	public @NonNull Collection<@NonNull Object> getRootObjects(@NonNull String modelName) {
+		return getTypedModelInstance(modelName).getRootObjects();
+	}
+
+	@Override
+	public @NonNull Model getTypedModelInstance(@NonNull String modelName) {
 		Integer modelIndex = modelIndexes.get(modelName);
 		if (modelIndex == null) {
 			throw new IllegalStateException("Unknown model name '" + modelName + "'");
 		}
-		return models[modelIndex].getRootObjects();
+		return models[modelIndex];
 	}
 
 	/**
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalConnectionInternal.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalConnectionInternal.java
index aaad51458..f3bb68e8b 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalConnectionInternal.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalConnectionInternal.java
@@ -63,6 +63,11 @@ public class IncrementalConnectionInternal extends AbstractIncrementalConnection
 		}
 	}
 
+	@Override
+	public void consume(int elementIndex, @NonNull Invocation invocation) {
+		super.consume(elementIndex, invocation);
+	}
+
 	/**
 	 * Remove, inverse append, the old anElement. The old value is removed,
 	 * its consumingInvocations are revoked so that their appends are also revoked.
@@ -76,7 +81,7 @@ public class IncrementalConnectionInternal extends AbstractIncrementalConnection
 				int jMax = valueAndConsumingInvocations.size();
 				for (int j = INDEX_INDEX+1; j < jMax; j++) {
 					AbstractInvocation.Incremental consumingInvocation = (AbstractInvocation.Incremental) valueAndConsumingInvocations.get(j);
-					consumingInvocation.revokeExecution();
+					consumingInvocation.destroy();
 				}
 				break;
 			}
@@ -103,8 +108,8 @@ public class IncrementalConnectionInternal extends AbstractIncrementalConnection
 	}
 
 	/**
-	 * Revoke, inverse append, the old value at connectionKey. The old value is removed,
-	 * its consumingInvocations are revoked so that their appends are also revoked.
+	 * Revoke, inverse append, the old value at connectionKey. The old object at copnnectionKey no longer exists.
+	 * Its consumingInvocations are destroyed.
 	 */
 	@Override
 	public synchronized void revoke(@NonNull Object connectionKey) {
@@ -114,7 +119,25 @@ public class IncrementalConnectionInternal extends AbstractIncrementalConnection
 		int iMax = valueAndConsumingInvocations.size();
 		for (int i = INDEX_INDEX+1; i < iMax; i++) {
 			AbstractInvocation.Incremental consumingInvocation = (AbstractInvocation.Incremental) valueAndConsumingInvocations.get(i);
-			consumingInvocation.revokeExecution();
+			consumingInvocation.destroy();
+		}
+	}
+
+	@Override
+	public void revokeConsumer(@NonNull Object anElement, Invocation.@NonNull Incremental invocation) {	// FIXME Use connectionKey
+		for (int i = 0; i < listOfValueAndConsumingInvocations.size(); i++) {
+			List<@NonNull Object> valueAndConsumingInvocations = listOfValueAndConsumingInvocations.get(i);
+			if ((valueAndConsumingInvocations != null) && (valueAndConsumingInvocations.get(VALUE_INDEX) == anElement)) {
+				int jMax = valueAndConsumingInvocations.size();
+				for (int j = INDEX_INDEX+1; j < jMax; j++) {
+					AbstractInvocation.Incremental consumingInvocation = (AbstractInvocation.Incremental) valueAndConsumingInvocations.get(j);
+					if (consumingInvocation == invocation) {
+						valueAndConsumingInvocations.remove(j);
+						break;
+					}
+				}
+				break;
+			}
 		}
 	}
 }
\ No newline at end of file
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalObjectManager.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalObjectManager.java
index f4a43b0e5..9bdf22f50 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalObjectManager.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/IncrementalObjectManager.java
@@ -21,6 +21,7 @@ import org.eclipse.emf.ecore.EReference;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
+import org.eclipse.ocl.pivot.internal.utilities.PivotUtilInternal;
 import org.eclipse.ocl.pivot.oclstdlib.OCLstdlibPackage;
 import org.eclipse.ocl.pivot.utilities.LabelUtil;
 import org.eclipse.qvtd.runtime.evaluation.AbstractObjectManager;
@@ -42,7 +43,7 @@ public class IncrementalObjectManager extends AbstractObjectManager
 		public enum SlotMode {
 			ASSIGNABLE,		// No assignment has been performed, object reads are blocked (collections reads may be unblocked)
 			ASSIGNED,		// Last assignment has been performed, reads are unblocked
-			REASSIGNABLE,	// No assignment has been performed by a re-execution, object reads are blocked (collections reads may be unblocked)
+			REASSIGNABLE	// No assignment has been performed by a re-execution, object reads are blocked (collections reads may be unblocked)
 		}
 
 		protected final @NonNull Object eObject;
@@ -137,8 +138,11 @@ public class IncrementalObjectManager extends AbstractObjectManager
 
 		@Override
 		public void revokeAssigned() {
-			assert isAssigned();
+			SlotMode mode2 = mode;
 			mode = SlotMode.REASSIGNABLE;
+			if (mode2 == SlotMode.ASSIGNED) {
+				revokeTargets();
+			}
 		}
 
 		@Override
@@ -425,7 +429,7 @@ public class IncrementalObjectManager extends AbstractObjectManager
 				}
 			}
 			//			super.assigned(objectManager, eObject, eFeature, ecoreValue);
-			assignedElement(eObject, (EReference)eFeature, (EObject)ecoreValue);
+			assignedElement(eObject, (EReference)eFeature, /*(EObject)*/ecoreValue);
 		}
 
 		public void assignedElement(@NonNull Object eContainer, @NonNull EReference eReference, Object eObject) {
@@ -726,6 +730,19 @@ public class IncrementalObjectManager extends AbstractObjectManager
 		invocation.addWriteSlot(slotState);
 	}
 
+	public @Nullable Map<@NonNull EStructuralFeature, @NonNull BasicSlotState> basicGetObjectState(@NonNull Object eObject) {
+		return object2feature2slotState.get(eObject);
+	}
+
+	public @Nullable BasicSlotState basicGetSlotState(@NonNull Object eObject, @NonNull EStructuralFeature eFeature) {
+		assert eFeature != null;
+		Map<EStructuralFeature, BasicSlotState> objectState = basicGetObjectState(eObject);
+		if (objectState == null) {
+			return null;
+		}
+		return objectState.get(eFeature);
+	}
+
 	@NonNull BasicSlotState createManyToManySlotState(
 			@NonNull Object eObject, @NonNull EReference eFeature, @NonNull EReference eOppositeFeature) {
 		throw new UnsupportedOperationException();
@@ -769,7 +786,13 @@ public class IncrementalObjectManager extends AbstractObjectManager
 		invocation.addCreatedObject(eObject);
 	}
 
-	public @NonNull Map<EStructuralFeature, BasicSlotState> getObjectState(@NonNull Object eObject) {
+	@Override
+	public void destroyed(@NonNull Object eObject) {
+		PivotUtilInternal.resetContainer((EObject) eObject);
+		object2feature2slotState.remove(eObject);
+	}
+
+	public @NonNull Map<@NonNull EStructuralFeature, @NonNull BasicSlotState> getObjectState(@NonNull Object eObject) {
 		Map<@NonNull EStructuralFeature, @NonNull BasicSlotState> feature2state = object2feature2slotState.get(eObject);
 		if (feature2state == null) {
 			feature2state = new HashMap<@NonNull EStructuralFeature, @NonNull BasicSlotState>();
@@ -856,9 +879,11 @@ public class IncrementalObjectManager extends AbstractObjectManager
 	}
 
 	public void modified(@NonNull Object eObject, @NonNull EStructuralFeature eFeature) {
-		BasicSlotState slotState = getSlotState(eObject, eFeature);
-		for (Execution.@NonNull Incremental execution : slotState.getTargets()) {
-			execution.revokeExecution();
+		BasicSlotState slotState = basicGetSlotState(eObject, eFeature);
+		if (slotState != null) {
+			for (Execution.@NonNull Incremental execution : slotState.getTargets()) {
+				execution.revoke();
+			}
 		}
 	}
 }
\ No newline at end of file
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/LazyObjectManager.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/LazyObjectManager.java
index 8f93ab3a6..2560cacc3 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/LazyObjectManager.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/LazyObjectManager.java
@@ -160,15 +160,15 @@ public class LazyObjectManager extends AbstractObjectManager
 
 		public synchronized void assigned(@NonNull LazyObjectManager objectManager, @NonNull Object eObject, @NonNull EStructuralFeature eFeature, @Nullable Object ecoreValue) {
 			switch (mode) {
-			case ASSIGNABLE:
-				mode = SlotMode.ASSIGNED;
-				unblock(objectManager);
-				break;
-			case ASSIGNED:
-				if (!(eFeature instanceof EOppositeReferenceImpl)) {
-					System.out.println("Re-assignment of " + eFeature.getEContainingClass().getName() + "::" + eFeature.getName() + " for " + eObject + " with " + ecoreValue);
-				}
-				break;
+				case ASSIGNABLE:
+					mode = SlotMode.ASSIGNED;
+					unblock(objectManager);
+					break;
+				case ASSIGNED:
+					if (!(eFeature instanceof EOppositeReferenceImpl)) {
+						System.out.println("Re-assignment of " + eFeature.getEContainingClass().getName() + "::" + eFeature.getName() + " for " + eObject + " with " + ecoreValue);
+					}
+					break;
 			}
 		}
 
@@ -194,10 +194,10 @@ public class LazyObjectManager extends AbstractObjectManager
 		@Override
 		public synchronized void getting(@NonNull Object eObject, @NonNull EStructuralFeature eFeature) {
 			switch (mode) {
-			case ASSIGNABLE:
-				throw new InvocationFailedException(this);
-			case ASSIGNED:
-				break;
+				case ASSIGNABLE:
+					throw new InvocationFailedException(this);
+				case ASSIGNED:
+					break;
 			}
 		}
 
@@ -511,24 +511,24 @@ public class LazyObjectManager extends AbstractObjectManager
 		public void assignedElement(@NonNull Object eContainer, @NonNull EReference eReference, Object eObject) {
 			//			super.assigned(objectManager, eContainer, eReference, eObject);
 			switch (mode) {
-			case ASSIGNABLE:
-				mode = SlotMode.ASSIGNED;
-				unblock(LazyObjectManager.this);
-				break;
-			case ASSIGNED:
-				break;
+				case ASSIGNABLE:
+					mode = SlotMode.ASSIGNED;
+					unblock(LazyObjectManager.this);
+					break;
+				case ASSIGNED:
+					break;
 			}
 		}
 
 		@Override
 		public synchronized void getting(@NonNull Object eObject, @NonNull EStructuralFeature eFeature) {
 			switch (mode) {
-			case ASSIGNABLE:
-				mode = SlotMode.ASSIGNED;
-				unblock(LazyObjectManager.this);
-				break;
-			case ASSIGNED:
-				break;
+				case ASSIGNABLE:
+					mode = SlotMode.ASSIGNED;
+					unblock(LazyObjectManager.this);
+					break;
+				case ASSIGNED:
+					break;
 			}
 		}
 	}
@@ -892,6 +892,11 @@ public class LazyObjectManager extends AbstractObjectManager
 		// Ignore incremental API
 	}
 
+	@Override
+	public void destroyed(@NonNull Object eObject) {
+		// Ignore incremental API
+	}
+
 	protected @NonNull EReference getEOppositeReference(@NonNull EReference eReference) {
 		EReference eOppositeReference = eReference.getEOpposite();
 		if (eOppositeReference == null) {
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/ModificationMonitor.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/ModificationMonitor.java
index 7b0274c3e..70a0f4be9 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/ModificationMonitor.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/ModificationMonitor.java
@@ -1,5 +1,7 @@
 package org.eclipse.qvtd.runtime.internal.evaluation;
 
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.List;
 
 import org.eclipse.emf.common.notify.Adapter;
@@ -11,7 +13,9 @@ import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.ocl.pivot.utilities.TreeIterable;
+import org.eclipse.qvtd.runtime.evaluation.AbstractTransformer;
 import org.eclipse.qvtd.runtime.evaluation.TransformationExecutor;
+import org.eclipse.qvtd.runtime.evaluation.TypedModelInstance;
 
 /**
  * An adapter implementation for tracking resource modification.
@@ -30,7 +34,7 @@ public class ModificationMonitor implements Adapter
 		return null;
 	}
 
-	public static @NonNull ModificationMonitor getModificationMonitor(@NonNull Resource resource, @NonNull TransformationExecutor executor) {
+	public static @NonNull ModificationMonitor getModificationMonitor(@NonNull TypedModelInstance typedModelInstance, @NonNull Resource resource, @NonNull TransformationExecutor executor) {
 		List<Adapter> eAdapters = resource.eAdapters();
 		for (Adapter eAdapter : eAdapters) {
 			if (eAdapter instanceof ModificationMonitor) {
@@ -40,7 +44,7 @@ public class ModificationMonitor implements Adapter
 				}
 			}
 		}
-		ModificationMonitor monitor = new ModificationMonitor(resource, executor);
+		ModificationMonitor monitor = new ModificationMonitor(typedModelInstance, resource, executor);
 		for (@NonNull EObject eObject : new TreeIterable(resource)) {
 			eObject.eAdapters().add(monitor);
 		}
@@ -48,12 +52,41 @@ public class ModificationMonitor implements Adapter
 		return monitor;
 	}
 
-	private @NonNull Resource resource;
-	private @NonNull TransformationExecutor executor;
+	private final AbstractTransformerInternal.Model.@NonNull Incremental typedModelInstance;
+	private final @NonNull Resource resource;
+	private final @NonNull TransformationExecutor executor;
+	private final AbstractTransformer.@NonNull Incremental transformer;
+	//	private final @NonNull IncrementalInvocationManager invocationManager;
+	private final @NonNull IncrementalObjectManager objectManager;
+	private @Nullable Deque<@NonNull Notification> notifications = null;
+	private boolean isDisabled = false;
 
-	public ModificationMonitor(@NonNull Resource resource, @NonNull TransformationExecutor executor) {
+	public ModificationMonitor(@NonNull TypedModelInstance typedModelInstance, @NonNull Resource resource, @NonNull TransformationExecutor executor) {
+		this.typedModelInstance = (AbstractTransformerInternal.Model.Incremental)typedModelInstance;
 		this.resource = resource;
 		this.executor = executor;
+		this.transformer = (AbstractTransformer.Incremental) executor.getTransformer();
+		//		this.transformer = (AbstractTransformer.Incremental) typedModelInstance.getTransformer();
+		//		this.invocationManager = (IncrementalInvocationManager) transformer.getInvocationManager();
+		this.objectManager = (IncrementalObjectManager) transformer.getObjectManager();
+	}
+
+	protected void addEObject(@NonNull EObject newValue) {
+		for (@NonNull EObject eObject : new TreeIterable(newValue, true)) {
+			eObject.eAdapters().add(this);
+		}
+		typedModelInstance.add(newValue, false);
+		for (@NonNull EObject eObject : new TreeIterable(newValue, false)) {
+			typedModelInstance.add(eObject, true);
+		}
+	}
+
+	public void dispose() {
+		isDisabled = true;
+		Deque<@NonNull Notification> notifications2 = notifications;
+		if (notifications2 != null) {
+			notifications2.clear();
+		}
 	}
 
 	public @NonNull TransformationExecutor getExecutor() {
@@ -73,22 +106,55 @@ public class ModificationMonitor implements Adapter
 	@Override
 	public void notifyChanged(Notification notification)
 	{
-		if (!notification.isTouch())
-		{
-			Object notifier = notification.getNotifier();
-			assert notifier != null;
-			IncrementalObjectManager objectManager = (IncrementalObjectManager) executor.getTransformer().getObjectManager();
-			switch (notification.getEventType()) {
-				case Notification.ADD:
+		if (isDisabled) {
+			return;
+		}
+		assert notification != null;
+		if (notification.isTouch()) {
+			return;
+		}
+		Deque<@NonNull Notification> notifications2 = notifications;
+		assert notifications2 == null;
+		if (notifications2 != null) {
+			notifications2.add(notification);
+			return;
+		}
+		notifications2 = notifications = new ArrayDeque<>();
+		do {
+			int eventType = notification.getEventType();
+			switch (eventType) {
+				case Notification.ADD: {
+					EObject object2 = (EObject) notification.getNewValue();
+					assert object2 != null;
+					addEObject(object2);
+					break;
+				}
 				case Notification.REMOVE: {
+					EObject object2 = (EObject) notification.getOldValue();
+					assert object2 != null;
+					removeEObject(object2);
+					break;
+				}
+				case Notification.ADD_MANY: {
+					for (Object object : (Iterable<?>)notification.getNewValue()) {
+						EObject object2 = (EObject) object;
+						assert object2 != null;
+						addEObject(object2);
+					}
 					break;
 				}
-				case Notification.ADD_MANY:
 				case Notification.REMOVE_MANY: {
+					for (Object object : (Iterable<?>)notification.getOldValue()) {
+						EObject object2 = (EObject) object;
+						assert object2 != null;
+						removeEObject(object2);
+					}
 					break;
 				}
 				case Notification.SET:
 				case Notification.UNSET: {
+					Object notifier = notification.getNotifier();
+					assert notifier != null;
 					Object feature = notification.getFeature();
 					if (feature instanceof EStructuralFeature) {
 						objectManager.modified(notifier, (EStructuralFeature)feature);
@@ -96,6 +162,24 @@ public class ModificationMonitor implements Adapter
 					break;
 				}
 			}
+			notification = notifications2.peek() != null ? notifications2.pop() : null;
+		} while (notification != null);
+		notifications = null;
+	}
+
+	protected void removeEObject(@NonNull EObject oldValue) {
+		for (EObject eObject : new TreeIterable(oldValue, true)) {
+			eObject.eAdapters().remove(this);
+		}
+		//		if (feature instanceof EReference) {
+		//			EReference eReference = (EReference)feature;
+		//			if (eReference.isContainment()) {
+		IncrementalObjectManager objectManager = (IncrementalObjectManager)executor.getTransformer().getObjectManager();
+		//			}
+		//		}
+		for (EObject eObject : new TreeIterable(oldValue, true)) {
+			typedModelInstance.remove(eObject);
+			objectManager.destroyed(eObject);
 		}
 	}
 
diff --git a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/StrictIncrementalConnectionInternal.java b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/StrictIncrementalConnectionInternal.java
index 98ea08109..36c5c4427 100644
--- a/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/StrictIncrementalConnectionInternal.java
+++ b/plugins/org.eclipse.qvtd.runtime/src/org/eclipse/qvtd/runtime/internal/evaluation/StrictIncrementalConnectionInternal.java
@@ -128,7 +128,7 @@ public abstract class StrictIncrementalConnectionInternal extends AbstractIncrem
 		int iMax = valueAndConsumingInvocations.size();
 		for (int i = COUNT_INDEX+1; i < iMax; i++) {
 			AbstractInvocation.Incremental consumingInvocation = (AbstractInvocation.Incremental) valueAndConsumingInvocations.get(i);
-			consumingInvocation.revokeExecution();
+			consumingInvocation.revoke();
 		}
 	}
 }
\ No newline at end of file
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/.classpath b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/.classpath
index dab1cc829..b6d3429da 100644
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/.classpath
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/.classpath
@@ -12,5 +12,6 @@
 	</classpathentry>
 	<classpathentry excluding="**/*.launch" kind="src" path="src"/>
 	<classpathentry kind="src" path="src-gen"/>
+	<!--classpathentry kind="src" path="test-gen"/-->
 	<classpathentry kind="output" path="bin"/>
 </classpath>
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiCompilerTests.java b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiCompilerTests.java
index fbfb35bcc..69fdb45c4 100644
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiCompilerTests.java
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiCompilerTests.java
@@ -12,6 +12,9 @@ package org.eclipse.qvtd.xtext.qvtimperative.tests;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 
 import org.eclipse.emf.codegen.ecore.genmodel.GenModel;
@@ -22,12 +25,14 @@ import org.eclipse.emf.ecore.EClass;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.resource.ResourceSet;
+import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.ocl.examples.codegen.dynamic.OCL2JavaFileObject;
 import org.eclipse.ocl.examples.xtext.tests.TestUtil;
 import org.eclipse.ocl.pivot.internal.manager.MetamodelManagerInternal;
 import org.eclipse.ocl.pivot.internal.utilities.OCLInternal;
+import org.eclipse.ocl.pivot.internal.utilities.PivotUtilInternal;
 import org.eclipse.ocl.pivot.internal.validation.PivotEObjectValidator;
 import org.eclipse.ocl.pivot.oclstdlib.OCLstdlibTables;
 import org.eclipse.ocl.pivot.resource.ASResource;
@@ -48,8 +53,16 @@ import org.eclipse.qvtd.pivot.qvtimperative.QVTimperativePackage;
 import org.eclipse.qvtd.pivot.qvtimperative.evaluation.Execution2GraphVisitor;
 import org.eclipse.qvtd.pivot.qvtimperative.evaluation.QVTiEnvironmentFactory;
 import org.eclipse.qvtd.pivot.qvtimperative.evaluation.QVTiTransformationExecutor;
+import org.eclipse.qvtd.runtime.evaluation.AbstractTransformer;
+import org.eclipse.qvtd.runtime.evaluation.Connection;
+import org.eclipse.qvtd.runtime.evaluation.Interval;
+import org.eclipse.qvtd.runtime.evaluation.Invocation;
+import org.eclipse.qvtd.runtime.evaluation.InvocationManager;
+import org.eclipse.qvtd.runtime.evaluation.ObjectManager;
 import org.eclipse.qvtd.runtime.evaluation.TransformationExecutor;
 import org.eclipse.qvtd.runtime.evaluation.Transformer;
+import org.eclipse.qvtd.runtime.evaluation.TypedModelInstance;
+import org.eclipse.qvtd.runtime.internal.evaluation.AbstractInvocationManagerInternal;
 import org.eclipse.qvtd.runtime.internal.evaluation.ModificationMonitor;
 import org.eclipse.qvtd.xtext.qvtbase.tests.LoadTestCase;
 import org.eclipse.qvtd.xtext.qvtbase.tests.ModelNormalizer;
@@ -57,6 +70,8 @@ import org.eclipse.qvtd.xtext.qvtbase.tests.utilities.TestsXMLUtil;
 import org.eclipse.qvtd.xtext.qvtimperative.tests.ManualUML2RDBMS.ManualRDBMSNormalizer;
 import org.eclipse.qvtd.xtext.qvtimperative.tests.SimpleUML2RDBMS.SimpleRDBMSNormalizer;
 
+import com.google.common.collect.Iterables;
+
 import junit.framework.TestCase;
 
 /**
@@ -204,6 +219,20 @@ public class QVTiCompilerTests extends LoadTestCase
 		}
 	}
 
+	protected void checkCleared(@NonNull TransformationExecutor executor) {
+		AbstractInvocationManagerInternal invocationManager = (AbstractInvocationManagerInternal)executor.getTransformer().getInvocationManager();
+		Iterable<@NonNull Invocation> allInvocations = invocationManager.debugGetAllInvocations();
+		assertEquals("All invocations post-clear", 1, Iterables.size(allInvocations));
+		for (@NonNull Interval interval : invocationManager.getIntervals()) {
+			for (@NonNull Connection connection : interval.getConnections()) {
+				assertEquals("Connection '" + connection.getName() + "' post-clear", 0, connection.debugGetSize());
+			}
+		}
+		ObjectManager objectManager = executor.getTransformer().getObjectManager();
+		Iterable<@NonNull ? extends Object> allObjects = objectManager.getObjects();
+		assertEquals("All objects post-clear", 0, Iterables.size(allObjects));
+	}
+
 	protected @NonNull MyQVT createQVT() {
 		return new MyQVT(new MyQVTiEnvironmentFactory(getProjectMap(), null));
 	}
@@ -221,7 +250,7 @@ public class QVTiCompilerTests extends LoadTestCase
 		super.setUp();
 	}
 
-	public void testCG_HSV2HSL_qvti() throws Exception {
+	public void testQVTiCompiler_HSV2HLS_CG() throws Exception {
 		MyQVT myQVT = createQVT();
 		URI transformURI = getProjectFileURI("HSV2HSL/HSV2HSL.qvti");
 		URI genModelURI = getProjectFileURI("HSV2HSL/HSV2HSL.genmodel");
@@ -237,7 +266,7 @@ public class QVTiCompilerTests extends LoadTestCase
 		myQVT.dispose();
 	}
 
-	public void testCG_ClassesCS2AS_qvti() throws Exception {
+	public void testQVTiCompiler_ClassesCS2AS_CG() throws Exception {
 		MyQVT myQVT = createQVT();
 		URI transformURI = getProjectFileURI("ClassesCS2AS/ClassesCS2AS.qvti");
 		URI genModelURI = getProjectFileURI("ClassesCS2AS/ClassesCS2AS.genmodel");
@@ -246,7 +275,7 @@ public class QVTiCompilerTests extends LoadTestCase
 		myQVT.dispose();
 	}
 
-	public void testCG_ClassesCS2AS_bug459225() throws Exception {
+	public void testQVTiCompiler_ClassesCS2AS_bug459225_CG() throws Exception {
 		MyQVT myQVT = createQVT();
 		URI transformURI = getProjectFileURI("ClassesCS2AS/bug459225/ClassesCS2AS.qvti");
 		URI genModelURI = getProjectFileURI("ClassesCS2AS/ClassesCS2AS.genmodel");
@@ -262,7 +291,7 @@ public class QVTiCompilerTests extends LoadTestCase
 		myQVT.dispose();
 	}
 
-	public void testCG_ManualUML2RDBMS_qvti() throws Exception {
+	public void testQVTiCompiler_ManualUML2RDBMS_CG() throws Exception {
 		MyQVT myQVT = createQVT();
 		URI transformURI = getProjectFileURI("ManualUML2RDBMS/ManualUML2RDBMS.qvti");
 		URI genModelURI = getProjectFileURI("ManualUML2RDBMS/ManualUML2RDBMS.genmodel");
@@ -278,7 +307,7 @@ public class QVTiCompilerTests extends LoadTestCase
 		myQVT.dispose();
 	}
 
-	public void testCG_SimpleUML2RDBMS_qvti() throws Exception {
+	public void testQVTiCompiler_SimpleUML2RDBMS_CG() throws Exception {
 		MyQVT myQVT = createQVT();
 		URI transformURI = getProjectFileURI("SimpleUML2RDBMS/SimpleUML2RDBMS.qvti");
 		URI genModelURI = getProjectFileURI("SimpleUML2RDBMS/SimpleUML2RDBMS.genmodel");
@@ -294,14 +323,14 @@ public class QVTiCompilerTests extends LoadTestCase
 		myQVT.dispose();
 	}
 
-	public void testCG_Tree2TallTree_qvti() throws Exception {
+	public void testQVTiCompiler_Tree2TallTree_CG() throws Exception {
 		//		AbstractTransformer.INVOCATIONS.setState(true);
 		MyQVT myQVT = createQVT();
 		URI genModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.genmodel");
 		URI transformURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.qvti");
-		URI inputModelURI = getProjectFileURI("Tree2TallTree/Tree.xmi");
-		URI outputModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.xmi");
-		URI referenceModelURI = getProjectFileURI("Tree2TallTree/TallTreeValidate.xmi");
+		URI inputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree.xmi");
+		URI outputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTree.xmi");
+		URI referenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidate.xmi");
 		Transformation asTransformation = myQVT.loadTransformation(transformURI, genModelURI);
 		Class<? extends Transformer> txClass = myQVT.generateCode(asTransformation, false);
 		Transformer tx = myQVT.createTransformer(txClass);
@@ -312,25 +341,25 @@ public class QVTiCompilerTests extends LoadTestCase
 		myQVT.dispose();
 	}
 
-	public void testCG_Tree2TallTree_Incremental_qvti() throws Exception {
-		//		AbstractTransformer.INVOCATIONS.setState(true);
+	public void testQVTiCompiler_Tree2TallTree_Changed_CG() throws Exception {
 		MyQVT myQVT = createQVT();
 		URI genModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.genmodel");
 		URI transformURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.qvti");
-		URI inputModelURI = getProjectFileURI("Tree2TallTree/Tree.xmi");
-		URI outputModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.xmi");
-		URI outputModelURI2 = getProjectFileURI("Tree2TallTree/Tree2TallTree2.xmi");
-		URI referenceModelURI = getProjectFileURI("Tree2TallTree/TallTreeValidate.xmi");
-		URI referenceModelURI2 = getProjectFileURI("Tree2TallTree/TallTreeValidate2.xmi");
+		URI inputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree.xmi");
+		URI outputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTree.xmi");
+		URI changedOutputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTreeChanged.xmi");
+		URI referenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidate.xmi");
+		URI changedReferenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidateChanged.xmi");
 		Transformation asTransformation = myQVT.loadTransformation(transformURI, genModelURI);
 		Class<? extends Transformer> txClass = myQVT.generateCode(asTransformation, true);
 		Transformer tx = myQVT.createTransformer(txClass);
 		Resource inputResource = myQVT.loadInput(tx, "tree", inputModelURI);
 		tx.run();
-		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/Tree2TallTree-inc.graphml"));
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-inc.graphml"));
 		myQVT.saveOutput(tx, "talltree", outputModelURI, referenceModelURI, null);
 		TransformationExecutor executor = tx.getExecutor();
-		@SuppressWarnings("unused") ModificationMonitor monitor = ModificationMonitor.getModificationMonitor(inputResource, executor);
+		TypedModelInstance treeModel = tx.getTypedModelInstance("tree");
+		@SuppressWarnings("unused") ModificationMonitor monitor = ModificationMonitor.getModificationMonitor(treeModel, inputResource, executor);
 		int gotOne = 0;
 		for (EObject eObject : new TreeIterable(inputResource)) {
 			EClass eClass = eObject.eClass();
@@ -345,12 +374,95 @@ public class QVTiCompilerTests extends LoadTestCase
 		}
 		assert gotOne == 1;
 		executor.getTransformer().getInvocationManager().flush();
-		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/Tree2TallTree-inc2.graphml"));
-		myQVT.saveOutput(tx, "talltree", outputModelURI2, referenceModelURI2, null);
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-incChanged.graphml"));
+		myQVT.saveOutput(tx, "talltree", changedOutputModelURI, changedReferenceModelURI, null);
 		myQVT.dispose();
 	}
 
-	/*	public void testCG_Tree2TallTree_Incremental_qvti2() throws Exception {
+	public void testQVTiCompiler_Tree2TallTree_Copied_CG() throws Exception {
+		AbstractTransformer.INVOCATIONS.setState(true);
+		MyQVT myQVT = createQVT();
+		URI genModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.genmodel");
+		URI transformURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.qvti");
+		URI inputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree.xmi");
+		URI outputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTree.xmi");
+		URI clearedOutputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTreeCleared.xmi");
+		URI copiedOutputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTreeCopied.xmi");
+		URI referenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidate.xmi");
+		URI clearedReferenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidateCleared.xmi");
+		Transformation asTransformation = myQVT.loadTransformation(transformURI, genModelURI);
+		Class<? extends Transformer> txClass = myQVT.generateCode(asTransformation, true);
+		Transformer tx = myQVT.createTransformer(txClass);
+		Resource inputResource = myQVT.loadInput(tx, "tree", inputModelURI);
+		tx.run();
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-inc.graphml"));
+		myQVT.saveOutput(tx, "talltree", outputModelURI, referenceModelURI, null);
+		TransformationExecutor executor = tx.getExecutor();
+		TypedModelInstance treeModel = tx.getTypedModelInstance("tree");
+		@SuppressWarnings("unused") ModificationMonitor monitor = ModificationMonitor.getModificationMonitor(treeModel, inputResource, executor);
+		List<@NonNull EObject> contents = inputResource.getContents();
+		List<@NonNull EObject> oldContents = new ArrayList<>(contents);
+		Collection<@NonNull EObject> newContents = EcoreUtil.copyAll(oldContents);
+		contents.clear();
+
+		checkCleared(executor);
+		InvocationManager invocationManager = executor.getTransformer().getInvocationManager();
+
+		//		oldContents.addAll(newContents);
+		invocationManager.flush();
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-incCleared.graphml"));
+		myQVT.saveOutput(tx, "talltree", clearedOutputModelURI, clearedReferenceModelURI, null);
+
+		contents.addAll(newContents);
+		invocationManager.flush();
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-incCopied.graphml"));
+		myQVT.saveOutput(tx, "talltree", copiedOutputModelURI, referenceModelURI, null);
+
+
+		myQVT.dispose();
+	}
+
+	public void testQVTiCompiler_Tree2TallTree_Deleted_CG() throws Exception {
+		AbstractTransformer.INVOCATIONS.setState(true);
+		MyQVT myQVT = createQVT();
+		URI genModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.genmodel");
+		URI transformURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.qvti");
+		URI inputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree.xmi");
+		URI outputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTree.xmi");
+		URI deletedOutputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTreeDeleted.xmi");
+		URI referenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidate.xmi");
+		URI deletedReferenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidateDeleted.xmi");
+		Transformation asTransformation = myQVT.loadTransformation(transformURI, genModelURI);
+		Class<? extends Transformer> txClass = myQVT.generateCode(asTransformation, true);
+		Transformer tx = myQVT.createTransformer(txClass);
+		Resource inputResource = myQVT.loadInput(tx, "tree", inputModelURI);
+		tx.run();
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-inc.graphml"));
+		myQVT.saveOutput(tx, "talltree", outputModelURI, referenceModelURI, null);
+		TransformationExecutor executor = tx.getExecutor();
+		TypedModelInstance treeModel = tx.getTypedModelInstance("tree");
+		ModificationMonitor monitor = ModificationMonitor.getModificationMonitor(treeModel,inputResource, executor);
+		int gotOne = 0;
+		for (EObject eObject : new TreeIterable(inputResource)) {
+			EClass eClass = eObject.eClass();
+			if ("Node".equals(eClass.getName())) {
+				EAttribute nameAttribute = (EAttribute) eClass.getEStructuralFeature("name");
+				Object name = eObject.eGet(nameAttribute);
+				if ("n1.1.1".equals(name)) {
+					gotOne++;
+					PivotUtilInternal.resetContainer(eObject);
+				}
+			}
+		}
+		assert gotOne == 1;
+		executor.getTransformer().getInvocationManager().flush();
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-incDeleted.graphml"));
+		myQVT.saveOutput(tx, "talltree", deletedOutputModelURI, deletedReferenceModelURI, null);
+		monitor.dispose();
+		myQVT.dispose();
+	}
+
+	/*	public void testQVTiCompiler_Tree2TallTree_Incremental_CG2() throws Exception {
 		//		AbstractTransformer.INVOCATIONS.setState(true);
 		MyQVT myQVT = createQVT();
 		URI genModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.genmodel");
@@ -364,7 +476,7 @@ public class QVTiCompilerTests extends LoadTestCase
 		Transformer tx = myQVT.createTransformer(txClass);
 		Resource inputResource = myQVT.loadInput(tx, "tree", inputModelURI);
 		tx.run();
-		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/Tree2TallTree-inc.graphml"));
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-inc.graphml"));
 		myQVT.saveOutput(tx, "talltree", outputModelURI, referenceModelURI, null);
 		TransformationExecutor executor = tx.getExecutor();
 		ModificationMonitor monitor = ModificationMonitor.getModificationMonitor(inputResource, executor);
@@ -382,20 +494,20 @@ public class QVTiCompilerTests extends LoadTestCase
 		}
 		assert gotOne == 1;
 		executor.getTransformer().getInvocationManager().flush();
-		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/Tree2TallTree-inc2.graphml"));
+		Execution2GraphVisitor.writeGraphMLfile(tx, getProjectFileURI("Tree2TallTree/graphs/Tree2TallTree-inc2.graphml"));
 		myQVT.saveOutput(tx, "talltree", outputModelURI2, referenceModelURI2, null);
 		myQVT.dispose();
 	} */
 
-	public void testCG_Tree2TallTreeInstall_qvti() throws Exception {
+	/*	public void testQVTiCompiler_Tree2TallTreeInstall_CG() throws Exception {
 		//		AbstractTransformer.INVOCATIONS.setState(true);
 		MyQVT myQVT = createQVT();
 		URI genModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.genmodel");
 		URI transformURI = getProjectFileURI("Tree2TallTree/Tree2TallTreeInstall.qvti");
 
-		URI inputModelURI = getProjectFileURI("Tree2TallTree/Tree.xmi");
-		URI outputModelURI = getProjectFileURI("Tree2TallTree/Tree2TallTree.xmi");
-		URI referenceModelURI = getProjectFileURI("Tree2TallTree/TallTreeValidate.xmi");
+		URI inputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree.xmi");
+		URI outputModelURI = getProjectFileURI("Tree2TallTree/samples/Tree2TallTree.xmi");
+		URI referenceModelURI = getProjectFileURI("Tree2TallTree/samples/TallTreeValidate.xmi");
 		Transformation asTransformation = myQVT.loadTransformation(transformURI, genModelURI);
 		Class<? extends Transformer> txClass = myQVT.generateCode(asTransformation, true);
 		Transformer tx = myQVT.createTransformer(txClass);
@@ -403,5 +515,5 @@ public class QVTiCompilerTests extends LoadTestCase
 		tx.run();
 		myQVT.saveOutput(tx, "talltree", outputModelURI, referenceModelURI, null);
 		myQVT.dispose();
-	}
+	} */
 }
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiInterpreterTests.java b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiInterpreterTests.java
index 529dfabaa..665bae913 100644
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiInterpreterTests.java
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/QVTiInterpreterTests.java
@@ -190,7 +190,7 @@ public class QVTiInterpreterTests extends LoadTestCase
 				GraphMLBuilder s = new GraphMLBuilder();
 				//FIXME	        	getTransformationStatus().accept(new EvaluationStatus2GraphVisitor(s));
 				File projectFile = getProjectFile();
-				File graphFile = new File(projectFile.toString() + "/" + fileNamePrefix + transformation.getName() + "_" + mode + ".graphml");
+				File graphFile = new File(projectFile.toString() + "/" + fileNamePrefix + /*"graphs/" +*/ transformation.getName() + "_" + mode + ".graphml");
 				FileWriter writer = new FileWriter(graphFile);
 				writer.append(s.toString());
 				writer.close();
@@ -199,7 +199,7 @@ public class QVTiInterpreterTests extends LoadTestCase
 
 		public void writeExecutionGraphMLfile(@NonNull String suffix) {
 			@SuppressWarnings("null")@NonNull URI baseURI = getTransformation().eResource().getURI();
-			URI graphmlURI = URI.createURI(getTransformation().getName().replace("\n",  "_").replace("\\n",  "_") + suffix + ".graphml").resolve(baseURI);
+			URI graphmlURI = URI.createURI(/*"graphs/" +*/ getTransformation().getName().replace("\n",  "_").replace("\\n",  "_") + suffix + ".graphml").resolve(baseURI);
 			try {
 				OutputStream outputStream = URIConverter.INSTANCE.createOutputStream(graphmlURI);
 				GraphMLStringBuilder s = new GraphMLStringBuilder();
@@ -347,10 +347,10 @@ public class QVTiInterpreterTests extends LoadTestCase
 		//    	myQVT.getEnvironmentFactory().setEvaluationTracingEnabled(true);
 		MyQvtiExecutor testEvaluator = myQVT.createEvaluator("Tree2TallTree", "Tree2TallTree.qvti", QVTiIncrementalExecutor.Mode.INCREMENTAL);
 		testEvaluator.saveTransformation(null);
-		testEvaluator.loadModel("tree", "Tree.xmi");
-		testEvaluator.createModel("tree2talltree", "Tree2TallTree.xmi");
-		testEvaluator.createModel("talltree", "TallTree.xmi");
-		testEvaluator.loadReference("talltree", "TallTreeValidate.xmi");
+		testEvaluator.loadModel("tree", "samples/Tree.xmi");
+		testEvaluator.createModel("tree2talltree", "samples/Tree2TallTree.xmi");
+		testEvaluator.createModel("talltree", "samples/TallTree.xmi");
+		testEvaluator.loadReference("talltree", "samples/TallTreeValidate.xmi");
 		testEvaluator.test();
 		testEvaluator.writeExecutionGraphMLfile("-execution");
 		testEvaluator.dispose();
@@ -370,10 +370,10 @@ public class QVTiInterpreterTests extends LoadTestCase
 		//    	myQVT.getEnvironmentFactory().setEvaluationTracingEnabled(true);
 		MyQvtiExecutor testEvaluator = myQVT.createEvaluator("Tree2TallTree", "Tree2TallTree.qvti", QVTiIncrementalExecutor.Mode.LAZY);
 		testEvaluator.saveTransformation(null);
-		testEvaluator.loadModel("tree", "Tree.xmi");
-		testEvaluator.createModel("tree2talltree", "Tree2TallTree.xmi");
-		testEvaluator.createModel("talltree", "TallTree.xmi");
-		testEvaluator.loadReference("talltree", "TallTreeValidate.xmi");
+		testEvaluator.loadModel("tree", "samples/Tree.xmi");
+		testEvaluator.createModel("tree2talltree", "samples/Tree2TallTree.xmi");
+		testEvaluator.createModel("talltree", "samples/TallTree.xmi");
+		testEvaluator.loadReference("talltree", "samples/TallTreeValidate.xmi");
 		testEvaluator.test();
 		testEvaluator.dispose();
 
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree2TallTree.qvti b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree2TallTree.qvti
index e9e043b25..83e390a09 100644
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree2TallTree.qvti
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree2TallTree.qvti
@@ -9,31 +9,27 @@ transformation Tree2TallTree {
 }
 
 map __root__ in Tree2TallTree {
---    buffer nodes := tree.objectsOfKind(Node)->sortedBy(name);
-    buffer nodes := tree.objectsOfKind(Node);
-    for node : tree::Node in nodes {
-        call Node2MiddleNode {
-            node iterates node;
-        } 
+    append nodes : tree::Node;
+    buffer node2tallNodes : tree2talltree::Node2TallNode;
+    install Node2MiddleNode {
+        node consumes nodes;
+        node2tallNodes appendsTo node2tallNodes;	
     } 
-    for node : tree::Node in nodes {
-        call Edge2MiddleEdge {
-            node iterates node;
-        } 
+    install Edge2MiddleEdge {
+        node consumes nodes;
     } 
---    for node2tallNode : tree2talltree::Node2TallNode in tree2talltree.objectsOfKind(Node2TallNode)->sortedBy(name) {
-    for node2tallNode : tree2talltree::Node2TallNode in tree2talltree.objectsOfKind(Node2TallNode) {
-        call MiddleNode2TallNode {
-            node2tallNode iterates node2tallNode;	
-        } 
+    install MiddleNode2TallNode {
+        node2tallNode consumes node2tallNodes;	
     } 
 }
 
 map Node2MiddleNode in Tree2TallTree {
 	guard:tree node : Node; 
+	append node2tallNodes : tree2talltree::Node2TallNode; 
 	new:tree2talltree node2tallNode : Node2TallNode;
 	set node2tallNode.node := node;
 	set node2tallNode.name := node.name;
+	add node2tallNodes += node2tallNode;
 }
 
 map Edge2MiddleEdge in Tree2TallTree {
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree2TallTreeInstall.qvti b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree2TallTreeInstall.qvti
deleted file mode 100644
index e20da977a..000000000
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree2TallTreeInstall.qvti
+++ /dev/null
@@ -1,55 +0,0 @@
-import 'Tree.ecore'::tree;
-import 'TallTree.ecore'::talltree;
-import 'Tree2TallTree.ecore'::tree2talltree;
-
-transformation Tree2TallTreeInstall {
-	check tree imports tree;
-	enforce talltree imports talltree;
-	tree2talltree imports tree2talltree;
-}
-
-map __root__ in Tree2TallTreeInstall {
-    buffer nodes := tree.objectsOfKind(Node)->sortedBy(name);
-    buffer node2tallNodes : tree2talltree::Node2TallNode;
-    install Node2MiddleNode {
-        node consumes nodes;
-        node2tallNodes appendsTo node2tallNodes;	
-    } 
-    install Edge2MiddleEdge {
-        node consumes nodes;
-    } 
-    install MiddleNode2TallNode {
-        node2tallNode consumes node2tallNodes;	
-    } 
-}
-
-map Node2MiddleNode in Tree2TallTreeInstall {
-	guard:tree node : Node; 
-	append node2tallNodes : tree2talltree::Node2TallNode; 
-	new:tree2talltree node2tallNode : Node2TallNode;
-	set node2tallNode.node := node;
-	set node2tallNode.name := node.name;
-	add node2tallNodes += node2tallNode;
-}
-
-map Edge2MiddleEdge in Tree2TallTreeInstall {
-	guard:tree node : Node;
-	var node2tallNode : Node2TallNode := node.Node2TallNode;
-	check node.parent <> null;
-	notify set node2tallNode.parent := node.parent.Node2TallNode;
---		node2tallNode.name := node.name;
-}
-
-map MiddleNode2TallNode in Tree2TallTreeInstall {
-	guard:tree2talltree node2tallNode : Node2TallNode;
-	var tallNode_name : String := node2tallNode.name;
-	observe Node2TallNode::children, Node2TallNode::tallNode
-	var tallNode_children : Set(TallNode) := node2tallNode.children?.tallNode->asSet();
-	observe Node2TallNode::children, Node2TallNode::tallNode, TallNode::height
-	var tallNode_height : Integer := if node2tallNode.children->notEmpty() then node2tallNode.children.tallNode.height->max() + 1 else 0 endif;
-	new:talltree tallNode : TallNode;
-	notify set node2tallNode.tallNode := tallNode;
-	set	tallNode.name := tallNode_name;
-	set	tallNode.children := tallNode_children;
-	notify set tallNode.height := tallNode_height;
-}
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/TallTreeValidate.xmi b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidate.xmi
index 3e7b96d79..5b8623e1c 100644
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/TallTreeValidate.xmi
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidate.xmi
@@ -1,16 +1,16 @@
-<?xml version="1.0" encoding="ASCII"?>

-<talltree:TallNode

-	xmi:version="2.0"

-	xmlns:xmi="http://www.omg.org/XMI"

-	xmlns:talltree="http://www.eclipse.org/qvt/examples/0.1/TallTree"

-    xsi:schemaLocation="http://www.eclipse.org/qvt/examples/0.1/TallTree TallTree.ecore"

-	height="2"

-	name="n1">

-  <children

-	height="1"

-      name="n1.1">

-    <children

-	height="0"

-        name="n1.1.1"/>

-  </children>

-</talltree:TallNode>

+<?xml version="1.0" encoding="ASCII"?>
+<talltree:TallNode
+	xmi:version="2.0"
+	xmlns:xmi="http://www.omg.org/XMI"
+	xmlns:talltree="http://www.eclipse.org/qvt/examples/0.1/TallTree"
+    xsi:schemaLocation="http://www.eclipse.org/qvt/examples/0.1/TallTree ../TallTree.ecore"
+	height="2"
+	name="n1">
+  <children
+	height="1"
+      name="n1.1">
+    <children
+	height="0"
+        name="n1.1.1"/>
+  </children>
+</talltree:TallNode>
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/TallTreeValidate2.xmi b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateChanged.xmi
index 8f3351492..7351bcd94 100644
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/TallTreeValidate2.xmi
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateChanged.xmi
@@ -1,16 +1,16 @@
-<?xml version="1.0" encoding="ASCII"?>

-<talltree:TallNode

-	xmi:version="2.0"

-	xmlns:xmi="http://www.omg.org/XMI"

-	xmlns:talltree="http://www.eclipse.org/qvt/examples/0.1/TallTree"

-    xsi:schemaLocation="http://www.eclipse.org/qvt/examples/0.1/TallTree TallTree.ecore"

-	height="2"

-	name="n1">

-  <children

-	height="1"

-      name="x1.1">

-    <children

-	height="0"

-        name="n1.1.1"/>

-  </children>

-</talltree:TallNode>

+<?xml version="1.0" encoding="ASCII"?>
+<talltree:TallNode
+	xmi:version="2.0"
+	xmlns:xmi="http://www.omg.org/XMI"
+	xmlns:talltree="http://www.eclipse.org/qvt/examples/0.1/TallTree"
+    xsi:schemaLocation="http://www.eclipse.org/qvt/examples/0.1/TallTree ../TallTree.ecore"
+	height="2"
+	name="n1">
+  <children
+	height="1"
+      name="x1.1">
+    <children
+	height="0"
+        name="n1.1.1"/>
+  </children>
+</talltree:TallNode>
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateCleared.xmi b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateCleared.xmi
new file mode 100644
index 000000000..bf9abab34
--- /dev/null
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateCleared.xmi
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xmi:XMI xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI"/>
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateDeleted.xmi b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateDeleted.xmi
new file mode 100644
index 000000000..6c47ae6ea
--- /dev/null
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/TallTreeValidateDeleted.xmi
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="ASCII"?>
+<talltree:TallNode
+	xmi:version="2.0"
+	xmlns:xmi="http://www.omg.org/XMI"
+	xmlns:talltree="http://www.eclipse.org/qvt/examples/0.1/TallTree"
+    xsi:schemaLocation="http://www.eclipse.org/qvt/examples/0.1/TallTree ../TallTree.ecore"
+	height="1"
+	name="n1">
+  <children
+	height="0"
+      name="n1.1">
+  </children>
+</talltree:TallNode>
diff --git a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree.xmi b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/Tree.xmi
index 0e1d7f79a..d90834c8d 100644
--- a/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/Tree.xmi
+++ b/tests/org.eclipse.qvtd.xtext.qvtimperative.tests/src/org/eclipse/qvtd/xtext/qvtimperative/tests/Tree2TallTree/samples/Tree.xmi
@@ -1,13 +1,13 @@
-<?xml version="1.0" encoding="ASCII"?>

-<tree:Node xmi:version="2.0"

-    xmlns:xmi="http://www.omg.org/XMI"

-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

-    xmlns:tree="http://www.eclipse.org/qvt/examples/0.1/Tree"

-    xsi:schemaLocation="http://www.eclipse.org/qvt/examples/0.1/Tree Tree.ecore"

-    name="n1">

-  <children

-      name="n1.1">

-    <children

-        name="n1.1.1"/>

-  </children>

-</tree:Node>

+<?xml version="1.0" encoding="ASCII"?>
+<tree:Node xmi:version="2.0"
+    xmlns:xmi="http://www.omg.org/XMI"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:tree="http://www.eclipse.org/qvt/examples/0.1/Tree"
+    xsi:schemaLocation="http://www.eclipse.org/qvt/examples/0.1/Tree ../Tree.ecore"
+    name="n1">
+  <children
+      name="n1.1">
+    <children
+        name="n1.1.1"/>
+  </children>
+</tree:Node>