diff --git a/AlgebraicDataflowArchitectureModel/src/application/actions/JavaPrototypeGenerateAction.java b/AlgebraicDataflowArchitectureModel/src/application/actions/JavaPrototypeGenerateAction.java
index ddd22e4..4083dce 100644
--- a/AlgebraicDataflowArchitectureModel/src/application/actions/JavaPrototypeGenerateAction.java
+++ b/AlgebraicDataflowArchitectureModel/src/application/actions/JavaPrototypeGenerateAction.java
@@ -59,8 +59,8 @@
 			} else {
 				JavaCodeGenerator.resetMainTypeName();			// use the default main type's name.
 			}
-//			editor.setCodes(JavaMethodBodyGenerator.doGenerate(graph, model, JavaCodeGenerator.doGenerate(graph, model)));
-			editor.setCodes(new CodeGeneratorFromDataFlowGraph().generateCode(model, graph, new JavaSpecific()));
+			editor.setCodes(JavaMethodBodyGenerator.doGenerate(graph, model, JavaCodeGenerator.doGenerate(graph, model)));
+//			editor.setCodes(new CodeGeneratorFromDataFlowGraph().generateCode(model, graph, new JavaSpecific()));
 			ModelExtension.recoverModel(model);
 			for (CompilationUnit file : editor.getCodes()) {
 				System.out.println(file);
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
index 0e03b38..0d8b08f 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
@@ -256,17 +256,11 @@
 		mainConstructorBody.addStatement(langSpec.getFieldAccessor(nodeName) + langSpec.getAssignment() + langSpec.getConstructorInvocation(componentName, parameters) + langSpec.getStatementDelimiter());
 	}
 
-	protected void addReference(TypeDeclaration component, MethodDeclaration constructor, Node dstNode, ILanguageSpecific langSpec) {
-		ResourcePath dstRes = null;
-		String dstComponentName = null;
-		if (dstNode instanceof ResourceNode) {
-			dstRes = ((ResourceNode) dstNode).getOutSideResource();
-			if (generatesComponent(dstRes.getResourceHierarchy())) {
-				dstComponentName = getComponentName(((ResourceNode) dstNode).getResourceHierarchy(), langSpec);
-			} else {
-				dstComponentName = getComponentName(((ResourceNode) dstNode).getResourceHierarchy().getParent(), langSpec);
-			}
+	protected ResourcePath addReference(TypeDeclaration component, MethodDeclaration constructor, ResourcePath dstRes, ILanguageSpecific langSpec) {
+		if (!generatesComponent(dstRes.getResourceHierarchy())) {
+			dstRes = dstRes.getParent();
 		}
+		String dstComponentName = getComponentName(dstRes.getResourceHierarchy(), langSpec);
 		if (dstComponentName != null) {
 			String dstNodeName = langSpec.toVariableName(dstComponentName);
 			if (langSpec.declareField()) {
@@ -277,6 +271,7 @@
 			constructor.addParameter(langSpec.newVariableDeclaration(new Type(dstComponentName, dstComponentName), dstNodeName));
 			constructor.getBody().addStatement(langSpec.getFieldAccessor(dstNodeName) + langSpec.getAssignment() + dstNodeName + langSpec.getStatementDelimiter());
 		}
+		return dstRes;
 	}
 
 	protected void fillStateGetterMethod(MethodDeclaration stateGetter, ResourceHierarchy resourceHierarchy, Type resStateType, ILanguageSpecific langSpec) {
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java b/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java
index 00b9406..0399394 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java
@@ -6,6 +6,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 
 import code.ast.Block;
@@ -158,12 +159,27 @@
 					break;
 				}
 			}
+			// Check if the output resource is outside of the channel scope.
+			boolean outsideOutputResource = false;
+			for (ChannelMember cm: ch.getOutputChannelMembers()) {
+				if (cm.getResource().getResourceHierarchy().equals(resourceNode.getOutSideResource().getResourceHierarchy()) && cm.isOutside()) {
+					outsideOutputResource = true;	// Regarded as push transfer.
+					break;
+				}
+			}
 			if (((PushPullAttribute) ((DataFlowEdge) resToCh).getAttribute()).getOptions().get(0) == PushPullValue.PUSH && !outsideInputResource) {
 				for (Edge chToRes: resToCh.getDestination().getOutEdges()) {
 					// for PUSH transfer
-					addReference(component, constructor, chToRes.getDestination(), langSpec);
-					ResourcePath dstRes = ((ResourceNode) chToRes.getDestination()).getOutSideResource();
-					if (!depends.contains(dstRes)) depends.add(dstRes);
+					if (chToRes.getDestination() instanceof ResourceNode) {
+						ResourcePath dstRes = addReference(component, constructor, ((ResourceNode) chToRes.getDestination()).getOutSideResource(), langSpec);
+						if (outsideOutputResource) {
+							if (dstRes != null && dstRes.getParent() != null) {
+								// Reference to root resource.
+								addReference(component, constructor, dstRes.getRoot(), langSpec);
+							}
+						}
+						if (!depends.contains(dstRes)) depends.add(dstRes);
+					}
 				}
 			}
 		}
@@ -171,7 +187,7 @@
 			for (Edge resToCh: chToRes.getSource().getInEdges()) {
 				ResourcePath srcRes = ((ResourceNode) resToCh.getSource()).getOutSideResource();
 				DataTransferChannel ch = ((ChannelNode) resToCh.getDestination()).getChannel();
-				// Check if the input and output resources are outside of the channel scope.
+				// Check if the input resource is outside of the channel scope.
 				boolean outsideInputResource = false;
 				for (ChannelMember cm: ch.getInputChannelMembers()) {
 					if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && cm.isOutside()) {
@@ -179,6 +195,7 @@
 						break;
 					}
 				}
+				// Check if the output resource is outside of the channel scope.
 				boolean outsideOutputResource = false;
 				for (ChannelMember cm: ch.getOutputChannelMembers()) {
 					if (cm.getResource().getResourceHierarchy().equals(resourceNode.getOutSideResource().getResourceHierarchy()) && cm.isOutside()) {
@@ -188,7 +205,13 @@
 				}
 				if ((((PushPullAttribute) ((DataFlowEdge) resToCh).getAttribute()).getOptions().get(0) != PushPullValue.PUSH && !outsideOutputResource) || outsideInputResource) {
 					// for PULL transfer
-					addReference(component, constructor, resToCh.getSource(), langSpec);
+					srcRes = addReference(component, constructor, ((ResourceNode) resToCh.getSource()).getOutSideResource(), langSpec);
+					if (outsideInputResource) {
+						if (srcRes != null & srcRes.getParent() != null) {
+							// Reference to root resource.
+							addReference(component, constructor, srcRes.getRoot(), langSpec);
+						}
+					}
 					if (!depends.contains(srcRes)) depends.add(srcRes);
 				}
 			}
@@ -244,13 +267,18 @@
 				if (outsideOutputResource) {
 					// Declare a field in the parent component to refer to the destination resource of push transfer.
 					String dstResName = null;
-					if (generatesComponent(dstRes.getResourceHierarchy())) {
-						dstResName = getComponentName(dstRes.getResourceHierarchy(), langSpec);
-					} else {
-						dstResName = getComponentName(dstRes.getResourceHierarchy().getParent(), langSpec);
+					if (!generatesComponent(dstRes.getResourceHierarchy())) {
+						dstRes = dstRes.getParent();
 					}
+					dstResName = getComponentName(dstRes.getResourceHierarchy(), langSpec);
 					FieldDeclaration refFieldForPush = langSpec.newFieldDeclaration(new Type(dstResName, dstResName), langSpec.toVariableName(dstResName));
 					fields.add(new AbstractMap.SimpleEntry(resourceNode.getParent().getResourceHierarchy(), refFieldForPush));
+					if (dstRes.getParent() != null) {
+						// Reference to root resource.
+						String dstRootResName = getComponentName(dstRes.getRoot().getResourceHierarchy(), langSpec);
+						FieldDeclaration refRootFieldForPush = langSpec.newFieldDeclaration(new Type(dstRootResName, dstRootResName), langSpec.toVariableName(dstRootResName));
+						fields.add(new AbstractMap.SimpleEntry(resourceNode.getParent().getResourceHierarchy(), refRootFieldForPush));
+					}
 				}
 			}
 		}
@@ -270,13 +298,18 @@
 				if (outsideInputResource) {
 					// Declare a field in the parent component to refer to the source resource of pull transfer.
 					String srcResName = null;
-					if (generatesComponent(srcRes.getResourceHierarchy())) {
-						srcResName = getComponentName(srcRes.getResourceHierarchy(), langSpec);
-					} else {
-						srcResName = getComponentName(srcRes.getResourceHierarchy().getParent(), langSpec);
+					if (!generatesComponent(srcRes.getResourceHierarchy())) {
+						srcRes = srcRes.getParent();
 					}
+					srcResName = getComponentName(srcRes.getResourceHierarchy(), langSpec);
 					FieldDeclaration refFieldForPull = langSpec.newFieldDeclaration(new Type(srcResName, srcResName), langSpec.toVariableName(srcResName));
 					fields.add(new AbstractMap.SimpleEntry(resourceNode.getParent().getResourceHierarchy(), refFieldForPull));
+					if (srcRes.getParent() != null) {
+						// Reference to root resource.
+						String srcRootResName = getComponentName(srcRes.getRoot().getResourceHierarchy(), langSpec);
+						FieldDeclaration refRootFieldForPull = langSpec.newFieldDeclaration(new Type(srcRootResName, srcRootResName), langSpec.toVariableName(srcRootResName));
+						fields.add(new AbstractMap.SimpleEntry(resourceNode.getParent().getResourceHierarchy(), refRootFieldForPull));
+					}
 					noPullTransfer = false;
 				}
 			}
@@ -497,16 +530,58 @@
 						}
 					}
 					
+					Set<ChannelMember> outsideInputMembers = new HashSet<>();
+					for (ChannelMember cm: ch.getInputChannelMembers()) {
+						if (cm.isOutside()) {
+							outsideInputMembers.add(cm);
+						}
+					}
+					if (outsideInputMembers.size() > 0) {
+						Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> resourcePaths = null;
+						for (ChannelMember out: ch.getOutputChannelMembers()) {
+							if (resourceNode.getInSideResources().contains(out.getResource())) {
+								try {
+									resourcePaths = ch.fillOutsideResourcePaths(out, getPullAccessor());
+								} catch (ParameterizedIdentifierIsFutureWork | ResolvingMultipleDefinitionIsFutureWork
+										| InvalidMessage | UnificationFailed | ValueUndefined e) {
+									e.printStackTrace();
+								}
+								break;
+							}
+						}
+						if (resourcePaths != null && resourcePaths.size() > 0) {
+							for (ChannelMember outsideMember: outsideInputMembers) {
+								for (ChannelMember dependingMember: resourcePaths.get(outsideMember).getValue()) {
+									if (dependingMember.getResource().equals(srcRes)) {
+										// An outside input resource path depends on srcRes.
+										ResourcePath outsidePath = resourcePaths.get(outsideMember).getKey();
+										String outsideResName = langSpec.toVariableName(getComponentName(outsidePath.getResourceHierarchy(), langSpec));
+										Expression outsideExp = getPullAccessor().getDirectStateAccessorFor(outsidePath, null);
+										if (generatesComponent(outsidePath.getResourceHierarchy())) {
+											outsideExp = ((Term) outsideExp).getChild(0);
+										}
+										String[] sideEffects = new String[] {""};
+										String outsideAccessor = outsideExp.toImplementation(sideEffects);
+										update.addStatement(langSpec.getFieldAccessor(outsideResName) + langSpec.getAssignment() + outsideAccessor + langSpec.getStatementDelimiter());		// change the reference field.
+									}
+								}
+							}
+						}
+					}
+					
 					// Add an invocation to another update method (for a chain of update method invocations).
 					for (Edge resToCh2: resourceNode.getOutEdges()) {
 						DataFlowEdge dOut = (DataFlowEdge) resToCh2;
 						DataTransferChannel ch2 = ((ChannelNode) resToCh2.getDestination()).getChannel();
 						// Check if the input resource is outside of the channel scope.
 						boolean outsideInputResource2 = false;
+						Set<ChannelMember> outsideInputMembers2 = new HashSet<>();
 						for (ChannelMember cm: ch2.getInputChannelMembers()) {
-							if (cm.getResource().getResourceHierarchy().equals(resourceNode.getResourceHierarchy()) && cm.isOutside()) {
-								outsideInputResource2 = true;	// Regarded as pull transfer.
-								break;
+							if (cm.isOutside()) {
+								outsideInputMembers2.add(cm);
+								if (cm.getResource().getResourceHierarchy().equals(resourceNode.getResourceHierarchy())) {
+									outsideInputResource2 = true;	// Regarded as pull transfer.
+								}
 							}
 						}
 						if (((PushPullAttribute) dOut.getAttribute()).getOptions().get(0) == PushPullValue.PUSH && !outsideInputResource2) {
@@ -548,6 +623,46 @@
 																					params) + langSpec.getStatementDelimiter());	// this.dst.updateSrc(value, refParams);
 							}
 						}
+						if (outsideInputMembers2.size() > 0) {
+							if (!generatesComponent(resourceNode.getResourceHierarchy())) {
+								ResourcePath srcRes2 = resourceNode.getOutSideResource();
+								for (ChannelMember out: ch2.getOutputChannelMembers()) {
+									if (!generatesComponent(out.getResource().getResourceHierarchy())) {
+										ResourcePath dstRes2 = out.getResource();
+										if (srcRes2.getParent().equals(dstRes2.getParent())) {
+											Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> resourcePaths = null;
+											try {
+												resourcePaths = ch2.fillOutsideResourcePaths(out, getPullAccessor());
+												if (resourcePaths != null && resourcePaths.size() > 0) {
+													for (ChannelMember outsideMember: outsideInputMembers2) {
+														for (ChannelMember dependingMember: resourcePaths.get(outsideMember).getValue()) {
+															if (dependingMember.getResource().equals(srcRes2)) {
+																// An outside input resource path depends on srcRes.
+																ResourcePath outsidePath = resourcePaths.get(outsideMember).getKey();
+																if (!generatesComponent(outsidePath.getResourceHierarchy())) {
+																	outsidePath = outsidePath.getParent();
+																}
+																String outsideResName = langSpec.toVariableName(getComponentName(outsidePath.getResourceHierarchy(), langSpec));
+																Expression outsideExp = getPullAccessor().getDirectStateAccessorFor(outsidePath, null);
+																if (generatesComponent(outsidePath.getResourceHierarchy())) {
+																	outsideExp = ((Term) outsideExp).getChild(0);
+																}
+																String[] sideEffects = new String[] {""};
+																String outsideAccessor = outsideExp.toImplementation(sideEffects);
+																update.addStatement(langSpec.getFieldAccessor(outsideResName) + langSpec.getAssignment() + outsideAccessor + langSpec.getStatementDelimiter());		// change the reference field.
+															}
+														}
+													}
+												}
+											} catch (ParameterizedIdentifierIsFutureWork | ResolvingMultipleDefinitionIsFutureWork
+													| InvalidMessage | UnificationFailed | ValueUndefined e) {
+												e.printStackTrace();
+											}
+										}
+									}
+								}
+							}
+						}
 					}
 				}
 			}
@@ -761,10 +876,13 @@
 							DataFlowEdge dOut = (DataFlowEdge) resToCh;
 							DataTransferChannel ch2 = ((ChannelNode) resToCh.getDestination()).getChannel();
 							boolean outsideInputResource2 = false;
+							Set<ChannelMember> outsideInputMembers2 = new HashSet<>();
 							for (ChannelMember cm: ch2.getInputChannelMembers()) {
-								if (cm.getResource().getResourceHierarchy().equals(resourceNode.getResourceHierarchy()) && cm.isOutside()) {
-									outsideInputResource2 = true;	// Regarded as pull transfer.
-									break;
+								if (cm.isOutside()) {
+									outsideInputMembers2.add(cm);
+									if (cm.getResource().getResourceHierarchy().equals(resourceNode.getResourceHierarchy())) {
+										outsideInputResource2 = true;	// Regarded as pull transfer.
+									}
 								}
 							}
 							if (((PushPullAttribute) dOut.getAttribute()).getOptions().get(0) == PushPullValue.PUSH && !outsideInputResource2) {
@@ -806,6 +924,46 @@
 																						params) + langSpec.getStatementDelimiter());	// this.dst.updateSrc(value, refParams);
 								}
 							}
+							if (outsideInputMembers2.size() > 0) {
+								if (!generatesComponent(resourceNode.getResourceHierarchy())) {
+									ResourcePath srcRes2 = resourceNode.getOutSideResource();
+									for (ChannelMember out2: ch2.getOutputChannelMembers()) {
+										if (!generatesComponent(out2.getResource().getResourceHierarchy())) {
+											ResourcePath dstRes2 = out2.getResource();
+											if (srcRes2.getParent().equals(dstRes2.getParent())) {
+												Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> resourcePaths = null;
+												try {
+													resourcePaths = ch2.fillOutsideResourcePaths(out2, getPullAccessor());
+													if (resourcePaths != null && resourcePaths.size() > 0) {
+														for (ChannelMember outsideMember: outsideInputMembers2) {
+															for (ChannelMember dependingMember: resourcePaths.get(outsideMember).getValue()) {
+																if (dependingMember.getResource().equals(srcRes2)) {
+																	// An outside input resource path depends on srcRes.
+																	ResourcePath outsidePath = resourcePaths.get(outsideMember).getKey();
+																	if (!generatesComponent(outsidePath.getResourceHierarchy())) {
+																		outsidePath = outsidePath.getParent();
+																	}
+																	String outsideResName = langSpec.toVariableName(getComponentName(outsidePath.getResourceHierarchy(), langSpec));
+																	Expression outsideExp = getPullAccessor().getDirectStateAccessorFor(outsidePath, null);
+																	if (generatesComponent(outsidePath.getResourceHierarchy())) {
+																		outsideExp = ((Term) outsideExp).getChild(0);
+																	}
+																	String[] sideEffects = new String[] {""};
+																	String outsideAccessor = outsideExp.toImplementation(sideEffects);
+																	input.addStatement(langSpec.getFieldAccessor(outsideResName) + langSpec.getAssignment() + outsideAccessor + langSpec.getStatementDelimiter());		// change the reference field.
+																}
+															}
+														}
+													}
+												} catch (ParameterizedIdentifierIsFutureWork | ResolvingMultipleDefinitionIsFutureWork
+														| InvalidMessage | UnificationFailed | ValueUndefined e) {
+													e.printStackTrace();
+												}
+											}
+										}
+									}
+								}
+							}
 						}
 					}
 				}
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
index b9cf60e..3b7f58c 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
@@ -232,20 +232,36 @@
 								break;
 							}
 						}
+						// Check if the output resource is outside of the channel scope.
+						boolean outsideOutputResource = false;
+						for (ChannelMember cm: ch.getOutputChannelMembers()) {
+							if (cm.getResource().getResourceHierarchy().equals(rn.getOutSideResource().getResourceHierarchy()) && cm.isOutside()) {
+								outsideOutputResource = true;	// Regarded as push transfer.
+								break;
+							}
+						}
 						if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH && !outsideInputResource) {
 							// Declare a field to refer to the destination resource of push transfer.
 							for (Edge chToRes: re.getDestination().getOutEdges()) {
 								ResourcePath dstRes = ((ResourceNode) chToRes.getDestination()).getOutSideResource();
-								String dstResName = null;
-								if (generatesComponent(dstRes.getResourceHierarchy())) {
-									dstResName = getComponentName(dstRes.getResourceHierarchy());
-								} else {
-									dstResName = getComponentName(dstRes.getResourceHierarchy().getParent());
+								if (!generatesComponent(dstRes.getResourceHierarchy())) {
+									dstRes = dstRes.getParent();
 								}
+								String dstResName = getComponentName(dstRes.getResourceHierarchy());
 								depends.add(dstRes);
 								component.addField(new FieldDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName)));
 								constructor.addParameter(new VariableDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName)));
 								block.addStatement("this." + toVariableName(dstResName) + " = " + toVariableName(dstResName) + ";");
+								if (outsideOutputResource) {
+									if (dstRes.getParent() != null) {
+										// Reference to root resource.
+										ResourcePath dstRootRes = dstRes.getRoot();
+										String dstRootResName = getComponentName(dstRootRes.getResourceHierarchy());
+										component.addField(new FieldDeclaration(new Type(dstRootResName, dstRootResName), toVariableName(dstRootResName)));
+										constructor.addParameter(new VariableDeclaration(new Type(dstRootResName, dstRootResName), toVariableName(dstRootResName)));
+										block.addStatement("this." + toVariableName(dstRootResName) + " = " + toVariableName(dstRootResName) + ";");
+									}
+								}
 							}
 						}
 					}
@@ -254,7 +270,7 @@
 							DataFlowEdge re = (DataFlowEdge) resToCh;
 							ResourcePath srcRes = ((ResourceNode) re.getSource()).getOutSideResource();
 							DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
-							// Check if the input and output resources are outside of the channel scope.
+							// Check if the input resource is outside of the channel scope.
 							boolean outsideInputResource = false;
 							for (ChannelMember cm: ch.getInputChannelMembers()) {
 								if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && cm.isOutside()) {
@@ -262,6 +278,7 @@
 									break;
 								}
 							}
+							// Check if the output resource is outside of the channel scope.
 							boolean outsideOutputResource = false;
 							for (ChannelMember cm: ch.getOutputChannelMembers()) {
 								if (cm.getResource().getResourceHierarchy().equals(rn.getOutSideResource().getResourceHierarchy()) && cm.isOutside()) {
@@ -270,17 +287,29 @@
 								}
 							}
 							String srcResName = null;
+							ResourcePath srcRes2 = srcRes;
 							if (generatesComponent(srcRes.getResourceHierarchy())) {
 								srcResName = getComponentName(srcRes.getResourceHierarchy());
 							} else {
-								srcResName = getComponentName(srcRes.getResourceHierarchy().getParent());
+								srcRes2 = srcRes.getParent();
+								srcResName = getComponentName(srcRes2.getResourceHierarchy());
 							}
 							if ((((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH && !outsideOutputResource) || outsideInputResource) {
 								// Declare a field to refer to the source resource of pull transfer.
-								depends.add(srcRes);
+								depends.add(srcRes2);
 								component.addField(new FieldDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName)));
 								constructor.addParameter(new VariableDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName)));
 								block.addStatement("this." + toVariableName(srcResName) + " = " + toVariableName(srcResName) + ";");
+								if (outsideInputResource) {
+									if (srcRes2.getParent() != null) {
+										// Reference to root resource.
+										ResourcePath srcRootRes = srcRes2.getRoot();
+										String srcRootResName = getComponentName(srcRootRes.getResourceHierarchy());
+										component.addField(new FieldDeclaration(new Type(srcRootResName, srcRootResName), toVariableName(srcRootResName)));
+										constructor.addParameter(new VariableDeclaration(new Type(srcRootResName, srcRootResName), toVariableName(srcRootResName)));
+										block.addStatement("this." + toVariableName(srcRootResName) + " = " + toVariableName(srcRootResName) + ";");
+									}
+								}
 							} else {
 								// Declare an update method in the type of the destination resource.
 								ArrayList<VariableDeclaration> vars = new ArrayList<>();
@@ -389,16 +418,21 @@
 								break;
 							}
 						}
-						if (outsideOutputResource) {
+						if (outsideOutputResource) {		// This logic may be incorrect. (ToDo)
 							// Declare a field in the parent component to refer to the destination resource of push transfer.
-							String dstResName = null;
-							if (generatesComponent(dstRes.getResourceHierarchy())) {
-								dstResName = getComponentName(dstRes.getResourceHierarchy());
-							} else {
-								dstResName = getComponentName(dstRes.getResourceHierarchy().getParent());
+							if (!generatesComponent(dstRes.getResourceHierarchy())) {
+								dstRes = dstRes.getParent();
 							}
+							String dstResName = getComponentName(dstRes.getResourceHierarchy());
 							FieldDeclaration refFieldForPush = new FieldDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName));
 							fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refFieldForPush));
+							if (dstRes.getParent() != null) {
+								// Reference to root resource.
+								ResourcePath dstRootRes = dstRes.getRoot();
+								String dstRootResName = getComponentName(dstRootRes.getResourceHierarchy());
+								FieldDeclaration refRootFieldForPush = new FieldDeclaration(new Type(dstRootResName, dstRootResName), toVariableName(dstRootResName));
+								fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refRootFieldForPush));
+							}
 						}
 					}
 				}
@@ -414,16 +448,21 @@
 								break;
 							}
 						}
-						if (outsideInputResource) {
+						if (outsideInputResource) {			// This logic may be incorrect. (ToDo)
 							// Declare a field in the parent component to refer to the source resource of pull transfer.
-							String srcResName = null;
-							if (generatesComponent(srcRes.getResourceHierarchy())) {
-								srcResName = getComponentName(srcRes.getResourceHierarchy());
-							} else {
-								srcResName = getComponentName(srcRes.getResourceHierarchy().getParent());
+							if (!generatesComponent(srcRes.getResourceHierarchy())) {
+								srcRes = srcRes.getParent();
 							}
+							String srcResName = getComponentName(srcRes.getResourceHierarchy());
 							FieldDeclaration refFieldForPull = new FieldDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName));
 							fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refFieldForPull));
+							if (srcRes.getParent() != null) {
+								// Reference to root resource.
+								ResourcePath srcRootRes = srcRes.getRoot();
+								String srcRootResName = getComponentName(srcRootRes.getResourceHierarchy());
+								FieldDeclaration refRootFieldForPull = new FieldDeclaration(new Type(srcRootResName, srcRootResName), toVariableName(srcRootResName));
+								fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refRootFieldForPull));
+							}
 							noPullTransfer = false;
 						}
 					}
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java
index 87791a0..1515354 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JavaMethodBodyGenerator.java
@@ -7,6 +7,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.Map.Entry;
 
 import code.ast.CompilationUnit;
 import code.ast.MethodDeclaration;
@@ -226,7 +227,7 @@
 									}
 									if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
 										boolean isContainedPush = false;
-										HashMap<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor = new HashMap<>();
+										Map<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor = new HashMap<>();
 										for (Edge chToRes2: dst.getInEdges()) {
 											DataTransferChannel ch2 = ((ChannelNode) chToRes2.getSource()).getChannel();
 											for (Edge resToCh2: chToRes2.getSource().getInEdges()) {
@@ -252,6 +253,7 @@
 										}
 										String[] sideEffects = new String[] {""};
 										// generate a return statement.
+										// An input resource is outside.
 										if (!isContainedPush) {
 											// All incoming edges are in PULL style.
 											String curState = ch.deriveUpdateExpressionOf(out, JavaCodeGenerator.pullAccessor).toImplementation(sideEffects);
@@ -262,6 +264,91 @@
 											getter.addStatement(sideEffects[0] + "return " + curState + ";");
 										}
 									}
+									if (outsideInputResource) {
+										Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> resourcePaths = ch.fillOutsideResourcePaths(out, JavaCodeGenerator.pullAccessor);
+										if (resourcePaths != null && resourcePaths.size() > 0) {
+											for (ChannelMember outsideMember: resourcePaths.keySet()) {
+												ResourcePath outsidePath = resourcePaths.get(outsideMember).getKey();
+												if (!JavaCodeGenerator.generatesComponent(outsidePath.getResourceHierarchy())) {
+													outsidePath = outsidePath.getParent();
+												}
+												String outsideResName = JavaCodeGenerator.toVariableName(JavaCodeGenerator.getComponentName(outsidePath.getResourceHierarchy()));
+												Set<ChannelMember> dependingMembers = resourcePaths.get(outsideMember).getValue();
+												for (ChannelMember dependingMember: dependingMembers) {
+													ResourcePath dependingRes = dependingMember.getResource();
+													ResourceNode dependingNode = null;
+													PushPullAttribute pushPull2 = null;
+													for (Edge resToCh2: resToCh.getDestination().getInEdges()) {
+														if (((ResourceNode) resToCh2.getSource()).getOutSideResource().equals(dependingRes)) {
+															dependingNode = (ResourceNode) resToCh2.getSource();
+															pushPull2 = (PushPullAttribute) resToCh.getAttribute();
+														}
+													}
+													TypeDeclaration dependingComponent = null;
+													if (JavaCodeGenerator.generatesComponent(dependingRes.getResourceHierarchy())) {
+														String dependingResourceName = JavaCodeGenerator.getComponentName(dependingRes.getResourceHierarchy());
+														dependingComponent = componentMap.get(dependingResourceName);
+													} else {
+														String dependingParentResourceName = JavaCodeGenerator.getComponentName(dependingRes.getParent().getResourceHierarchy());
+														dependingComponent = componentMap.get(dependingParentResourceName);
+													}
+													if (dstComponent == dependingComponent) {
+														// In the common parent.
+														if (dependingNode != null) {
+															// Inspect further dependency.
+															for (Edge chToRes2: dependingNode.getInEdges()) {
+																DataTransferChannel ch2 = ((ChannelNode) chToRes2.getSource()).getChannel();
+																if (ch2.getInputChannelMembers().size() == 0) {
+																	// In an input method.
+																	MethodDeclaration input = getInputMethod(dependingComponent, ch2.getOutputChannelMembers().iterator().next());
+																	Expression outsideExp = JavaCodeGenerator.pullAccessor.getDirectStateAccessorFor(outsidePath, null);
+																	if (JavaCodeGenerator.generatesComponent(outsidePath.getResourceHierarchy())) {
+																		outsideExp = ((Term) outsideExp).getChild(0);
+																	}
+																	String[] sideEffects = new String[] {""};
+																	String outsideAccessor = outsideExp.toImplementation(sideEffects);
+																	input.addStatement("this." + outsideResName + " = " + outsideAccessor + ";");		// change the reference field.
+																} else {
+																	boolean isPush = true;
+																	for (Edge resToCh2: chToRes2.getSource().getInEdges()) {
+																		if (((PushPullAttribute) resToCh2.getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
+																			isPush = false;
+																			break;
+																		}
+																	}
+																	if (isPush) {
+																		for (Edge resToCh2: chToRes2.getSource().getInEdges()) {
+																			// In an update method.
+																			ResourceNode dependingResSrc = (ResourceNode) resToCh2.getSource();
+																			MethodDeclaration update = getUpdateMethod(dependingComponent, JavaCodeGenerator.getComponentName(dependingResSrc.getResourceHierarchy()));
+																			Expression outsideExp = JavaCodeGenerator.pullAccessor.getDirectStateAccessorFor(outsidePath, null);
+																			if (JavaCodeGenerator.generatesComponent(outsidePath.getResourceHierarchy())) {
+																				outsideExp = ((Term) outsideExp).getChild(0);
+																			}
+																			String[] sideEffects = new String[] {""};
+																			String outsideAccessor = outsideExp.toImplementation(sideEffects);
+																			update.addStatement("this." + outsideResName + " = " + outsideAccessor + ";");		// change the reference field.
+																		}
+																	}
+																}
+															}
+														}
+													} else {
+														if (pushPull2.getOptions().get(0) == PushPullValue.PUSH) {
+															MethodDeclaration update = getUpdateMethod(dstComponent, JavaCodeGenerator.getComponentName(dependingRes.getResourceHierarchy()));
+															Expression outsideExp = JavaCodeGenerator.pullAccessor.getDirectStateAccessorFor(outsidePath, null);
+															if (JavaCodeGenerator.generatesComponent(outsidePath.getResourceHierarchy())) {
+																outsideExp = ((Term) outsideExp).getChild(0);
+															}
+															String[] sideEffects = new String[] {""};
+															String outsideAccessor = outsideExp.toImplementation(sideEffects);
+															update.addStatement("this." + outsideResName + " = " + outsideAccessor + ";");		// change the reference field.
+														}
+													}
+												}
+											}
+										}										
+									}
 								}
 							}
 						}
@@ -520,13 +607,28 @@
 		return inputs;
 	}
 
-	private static MethodDeclaration getInputMethod(TypeDeclaration component, ChannelMember out) {
+	private static List<MethodDeclaration> getInputMethods(TypeDeclaration component, ResourceHierarchy resource, DataTransferModel model) {
+		List<MethodDeclaration> inputs = new ArrayList<>();
+		for (Channel c: model.getIOChannels()) {
+			DataTransferChannel channel = (DataTransferChannel) c;
+			// I/O channel
+			for (ChannelMember out: channel.getOutputChannelMembers()) {
+				if (resource.equals(out.getResource().getResourceHierarchy())) {
+					MethodDeclaration input = getInputMethod(component, out);
+					inputs.add(input);
+				}
+			}
+		}
+		return inputs;
+	}
+
+	private static MethodDeclaration getInputMethod(TypeDeclaration component, ChannelMember cm) {
 		MethodDeclaration input = null;
-		if (out.getStateTransition().getMessageExpression() instanceof Term) {
-			Term message = (Term) out.getStateTransition().getMessageExpression();
+		if (cm.getStateTransition().getMessageExpression() instanceof Term) {
+			Term message = (Term) cm.getStateTransition().getMessageExpression();
 			input = getMethod(component, message.getSymbol().getImplName());
-		} else if (out.getStateTransition().getMessageExpression() instanceof Variable) {
-			Variable message = (Variable) out.getStateTransition().getMessageExpression();
+		} else if (cm.getStateTransition().getMessageExpression() instanceof Variable) {
+			Variable message = (Variable) cm.getStateTransition().getMessageExpression();
 			input = getMethod(component, message.getName());
 		}
 		return input;
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java
index 9a01dd3..17710f0 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JerseyMethodBodyGenerator.java
@@ -6,6 +6,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 
 import algorithms.TypeInference;
@@ -341,8 +342,8 @@
 									}
 									if (getter.getBody() == null || getter.getBody().getStatements().size() == 0) {
 										// generate a return statement.
-										Map<ChannelMember, ResourcePath> resourcePaths = new HashMap<>();
-										Expression curExp = ch.deriveUpdateExpressionAndConcreteResourcePathsOf(out, JerseyCodeGenerator.pullAccessor, resourcePaths);		// no pull data transfer is included.
+										Expression curExp = ch.deriveUpdateExpressionOf(out, JerseyCodeGenerator.pullAccessor);		// no pull data transfer is included.
+										Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> resourcePaths = ch.fillOutsideResourcePaths(out, JerseyCodeGenerator.pullAccessor);
 										String[] sideEffects = new String[] {""};
 										String curState = curExp.toImplementation(sideEffects);
 										getter.addStatement(sideEffects[0] + "return " + curState + ";");
@@ -352,9 +353,9 @@
 											Type refResourceType = c.getResource().getResourceStateType();
 											generatePullDataTransfer(getter, refResourceName, refResourceName, refResourceType);
 										}
-										for (Map.Entry<ChannelMember, ResourcePath> pathEnt: resourcePaths.entrySet()) {
+										for (Entry<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> pathEnt: resourcePaths.entrySet()) {
 											ChannelMember cm = pathEnt.getKey();
-											ResourcePath src2 = pathEnt.getValue();
+											ResourcePath src2 = pathEnt.getValue().getKey();
 											// get outside src resource state by pull data transfer.
 											if (cm.isOutside() || src2.getCommonPrefix(dst.getOutSideResource()) == null) {
 												Type srcResourceType = src2.getResourceStateType();
diff --git a/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java b/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java
index 0a7c10b..de90a73 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/algebra/Position.java
@@ -28,6 +28,14 @@
 	public boolean isEmpty() {
 		return (orders == null || orders.size() == 0);
 	}
+
+	public boolean isAncestorOf(Position another) {
+		if (another.orders.size() < this.orders.size()) return false;
+		for (int i = 0; i < orders.size(); i++) {
+			if (this.orders.get(i) != another.orders.get(i)) return false;
+		}
+		return true;
+	}
 	
 	public Object clone() {
 		return new Position((ArrayList<Integer>) orders.clone());
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/StateTransition.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/StateTransition.java
index 065525c..0186360 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/StateTransition.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/StateTransition.java
@@ -3,6 +3,7 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map.Entry;
+import java.util.Set;
 
 import models.algebra.Constant;
 import models.algebra.Expression;
@@ -49,7 +50,7 @@
 		return true;
 	}
 
-	public Expression deriveMessageConstraintFor(Expression curStateValue, Expression nextStateValue) throws InvalidMessage, ResolvingMultipleDefinitionIsFutureWork {
+	public Expression deriveMessageConstraintFor(Expression curStateValue, Expression nextStateValue, Set<Position> substitutedPositions) throws InvalidMessage, ResolvingMultipleDefinitionIsFutureWork {
 		HashMap<Variable, ArrayList<Expression>> bindings = new HashMap<>();
 		
 		Expression curStateTerm = getCurStateExpression();
@@ -104,24 +105,10 @@
 		}
 		
 		Expression messageTerm = getMessageExpression();
-		if (!(messageTerm instanceof Term) && !(messageTerm instanceof Variable)) throw new InvalidMessage();
-		HashMap<Position, Variable> messageVars = messageTerm.getVariables();
-		for (Variable var: messageVars.values()) {
-			if (bindings.get(var) != null) {
-				if (bindings.get(var).size() > 1) throw new ResolvingMultipleDefinitionIsFutureWork();
-				if (messageTerm instanceof Term) {
-					messageTerm = ((Term) messageTerm).substitute(var, bindings.get(var).iterator().next());
-				} else if (messageTerm instanceof Variable) {
-					if (messageTerm.equals(var)) {
-						return bindings.get(var).iterator().next();
-					}
-				}
-			}
-		}
-		return messageTerm;
+		return substituteValues(messageTerm, bindings, substitutedPositions);
 	}
 
-	public Expression deriveMessageConstraintFor(Expression curStateValue) throws InvalidMessage, ResolvingMultipleDefinitionIsFutureWork {
+	public Expression deriveMessageConstraintFor(Expression curStateValue, Set<Position> substitutedPositions) throws InvalidMessage, ResolvingMultipleDefinitionIsFutureWork {
 		HashMap<Variable, ArrayList<Expression>> bindings = new HashMap<>();
 		
 		Expression curStateTerm = getCurStateExpression();
@@ -144,15 +131,23 @@
 		}
 		
 		Expression messageTerm = getMessageExpression();
+		return substituteValues(messageTerm, bindings, substitutedPositions);
+	}
+
+	private Expression substituteValues(Expression messageTerm, HashMap<Variable, ArrayList<Expression>> bindings, Set<Position> substitutedPositions)
+			throws InvalidMessage, ResolvingMultipleDefinitionIsFutureWork {
 		if (!(messageTerm instanceof Term) && !(messageTerm instanceof Variable)) throw new InvalidMessage();
 		HashMap<Position, Variable> messageVars = messageTerm.getVariables();
-		for (Variable var: messageVars.values()) {
+		for (Entry<Position, Variable> varEnt: messageVars.entrySet()) {
+			Variable var = varEnt.getValue();
 			if (bindings.get(var) != null) {
 				if (bindings.get(var).size() > 1) throw new ResolvingMultipleDefinitionIsFutureWork();
 				if (messageTerm instanceof Term) {
+					substitutedPositions.add(varEnt.getKey());
 					messageTerm = ((Term) messageTerm).substitute(var, bindings.get(var).iterator().next());
 				} else if (messageTerm instanceof Variable) {
 					if (messageTerm.equals(var)) {
+						substitutedPositions.add(new Position());
 						return bindings.get(var).iterator().next();
 					}
 				}
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java b/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
index 892a2f6..ce8c581 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataFlowModel/DataTransferChannel.java
@@ -1,5 +1,7 @@
 package models.dataFlowModel;
 
+import java.util.AbstractMap;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -210,10 +212,28 @@
 			throws ParameterizedIdentifierIsFutureWork, ResolvingMultipleDefinitionIsFutureWork, InvalidMessage, UnificationFailed, ValueUndefined {
 		return deriveUpdateExpressionOf(targetMember, stateAccessor, null);
 	}
+
+	public Expression deriveUpdateExpressionOf(ChannelMember targetMember, IResourceStateAccessor stateAccessor, Map<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor) 
+			throws ParameterizedIdentifierIsFutureWork, ResolvingMultipleDefinitionIsFutureWork, InvalidMessage, UnificationFailed, ValueUndefined {
+		if (!getOutputChannelMembers().contains(targetMember)) return null;
+		
+		// Calculate unified message constraints
+		Map<ChannelMember, Set<Position>> substitutedPositionsFromChannels = new HashMap<>();
+		Term unifiedMessage = calcUnifiedMessage(targetMember, stateAccessor, inputResourceToStateAccessor, substitutedPositionsFromChannels);
+		
+		// Calculate the next state of target resource from the unified message and the current resource state
+		Expression curOutputStateAccessor = stateAccessor.getCurrentStateAccessorFor(targetMember, targetMember);
+		if (unifiedMessage == null) {
+			// for IOChannel
+			if (targetMember.getStateTransition().getMessageExpression() instanceof Term) {
+				unifiedMessage = (Term) targetMember.getStateTransition().getMessageExpression();
+			}
+		}
+		return targetMember.getStateTransition().deriveNextStateExpressionFor(curOutputStateAccessor, unifiedMessage);
+	}
 	
 	/**
-	 * Derive the state update calculation of the target channel member and the filled outside resource paths with a given resource push/pull state accessor.
-	 * @param targetMember a channel member whose state is to be updated
+	 * Fill outside resource paths with a given resource push/pull state accessor.
 	 * @param stateAccessor a push/pull resource state accessor
 	 * @param resourcePaths a container to be returned with filled outside resource paths
 	 * @return the derived update calculation
@@ -223,70 +243,87 @@
 	 * @throws UnificationFailed
 	 * @throws ValueUndefined
 	 */
-	public Expression deriveUpdateExpressionAndConcreteResourcePathsOf(ChannelMember targetMember, IResourceStateAccessor stateAccessor,  Map<ChannelMember, ResourcePath> resourcePaths) 
+	public Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> fillOutsideResourcePaths(ChannelMember targetMember, IResourceStateAccessor stateAccessor) 
 			throws ParameterizedIdentifierIsFutureWork, ResolvingMultipleDefinitionIsFutureWork, InvalidMessage, UnificationFailed, ValueUndefined {		
-		return deriveUpdateExpressionAndConcreteResourcePathsOf(targetMember, stateAccessor, null, resourcePaths);
+		return fillOutsideResourcePaths(targetMember, stateAccessor, null);
 	}
 
-	public Expression deriveUpdateExpressionOf(ChannelMember targetMember, IResourceStateAccessor stateAccessor, HashMap<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor) 
+	public Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> fillOutsideResourcePaths(ChannelMember targetMember, IResourceStateAccessor stateAccessor, Map<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor) 
 			throws ParameterizedIdentifierIsFutureWork, ResolvingMultipleDefinitionIsFutureWork, InvalidMessage, UnificationFailed, ValueUndefined {
 		if (!getOutputChannelMembers().contains(targetMember)) return null;
-		
-		// Calculate unified message constraints
-		Term unifiedMessage = calcUnifiedMessage(targetMember, stateAccessor, inputResourceToStateAccessor);
-		
-		// Calculate the next state of target resource from the unified message and the current resource state
-		Expression curOutputStateAccessor = stateAccessor.getCurrentStateAccessorFor(targetMember, targetMember);
-		if (unifiedMessage == null) {
-			// for IOChannel
-			if (targetMember.getStateTransition().getMessageExpression() instanceof Term) {
-				unifiedMessage = (Term) targetMember.getStateTransition().getMessageExpression();
-			}
-		}
-		return targetMember.getStateTransition().deriveNextStateExpressionFor(curOutputStateAccessor, unifiedMessage);
-	}
-
-	public Expression deriveUpdateExpressionAndConcreteResourcePathsOf(ChannelMember targetMember, IResourceStateAccessor stateAccessor, HashMap<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor, Map<ChannelMember, ResourcePath> resourcePaths) 
-			throws ParameterizedIdentifierIsFutureWork, ResolvingMultipleDefinitionIsFutureWork, InvalidMessage, UnificationFailed, ValueUndefined {
-		if (!getOutputChannelMembers().contains(targetMember)) return null;
+		Map<ChannelMember, Entry<ResourcePath, Set<ChannelMember>>> resourcePaths = new HashMap<>();
 		
 		// Calculate unified message constraints from input and reference state transitions
-		Term unifiedMessage = calcUnifiedMessage(targetMember, stateAccessor, inputResourceToStateAccessor);
+		Map<ChannelMember, Set<Position>> substitutedPositionsFromChannels = new HashMap<>();
+		Term unifiedMessage = calcUnifiedMessage(targetMember, stateAccessor, inputResourceToStateAccessor, substitutedPositionsFromChannels);
 		
 		// Fill outside resource paths
 		if (unifiedMessage != null) {
 			for (ChannelMember cm: getInputChannelMembers()) {
 				if (cm.isOutside()) {
-					resourcePaths.put(cm, fillOutsideResourcePath(cm.getResource(), unifiedMessage, targetMember.getStateTransition().getMessageExpression()));
+					Set<Position> dependingVarPos = new HashSet<>();
+					ResourcePath filledResPath = fillOutsideResourcePath(cm.getResource(), unifiedMessage, targetMember.getStateTransition().getMessageExpression(), dependingVarPos);
+					Set<ChannelMember> dependingChannelMembers =  new HashSet<>();
+					for (ChannelMember otherCm: substitutedPositionsFromChannels.keySet()) {
+						for (Position otherPos: substitutedPositionsFromChannels.get(otherCm)) {
+							for (Position thisPos: dependingVarPos) {
+								if (thisPos.isAncestorOf(otherPos)) {
+									dependingChannelMembers.add(otherCm);
+									break;
+								}
+							}
+							if (dependingChannelMembers.contains(otherCm)) break;
+						}
+					}
+					resourcePaths.put(cm, new AbstractMap.SimpleEntry(filledResPath, dependingChannelMembers));
 				}
 			}
 			for (ChannelMember cm: getReferenceChannelMembers()) {
 				if (cm.isOutside()) {
-					resourcePaths.put(cm, fillOutsideResourcePath(cm.getResource(), unifiedMessage, targetMember.getStateTransition().getMessageExpression()));
+					Set<Position> dependingVarPos = new HashSet<>();
+					ResourcePath filledResPath = fillOutsideResourcePath(cm.getResource(), unifiedMessage, targetMember.getStateTransition().getMessageExpression(), dependingVarPos);
+					Set<ChannelMember> dependingChannelMembers =  new HashSet<>();
+					for (ChannelMember otherCm: substitutedPositionsFromChannels.keySet()) {
+						for (Position otherPos: substitutedPositionsFromChannels.get(otherCm)) {
+							for (Position thisPos: dependingVarPos) {
+								if (thisPos.isAncestorOf(otherPos)) {
+									dependingChannelMembers.add(otherCm);
+									break;
+								}
+							}
+							if (dependingChannelMembers.contains(otherCm)) break;
+						}
+					}
+					resourcePaths.put(cm, new AbstractMap.SimpleEntry(filledResPath, dependingChannelMembers));
 				}
 			}
 			for (ChannelMember cm: getOutputChannelMembers()) {
 				if (cm.isOutside()) {
-					resourcePaths.put(cm, fillOutsideResourcePath(cm.getResource(), unifiedMessage, targetMember.getStateTransition().getMessageExpression()));
+					Set<Position> dependingVarPos = new HashSet<>();
+					ResourcePath filledResPath = fillOutsideResourcePath(cm.getResource(), unifiedMessage, targetMember.getStateTransition().getMessageExpression(), dependingVarPos);
+					Set<ChannelMember> dependingChannelMembers =  new HashSet<>();
+					for (ChannelMember otherCm: substitutedPositionsFromChannels.keySet()) {
+						for (Position otherPos: substitutedPositionsFromChannels.get(otherCm)) {
+							for (Position thisPos: dependingVarPos) {
+								if (thisPos.isAncestorOf(otherPos)) {
+									dependingChannelMembers.add(otherCm);
+									break;
+								}
+							}
+							if (dependingChannelMembers.contains(otherCm)) break;
+						}
+					}
+					resourcePaths.put(cm, new AbstractMap.SimpleEntry(filledResPath, dependingChannelMembers));
 				}
 			}
 		}
-		
-		// Calculate the next state of target resource from the unified message and the current resource state
-		Expression curOutputStateAccessor = stateAccessor.getCurrentStateAccessorFor(targetMember, targetMember);
-		if (unifiedMessage == null) {
-			// for IOChannel
-			if (targetMember.getStateTransition().getMessageExpression() instanceof Term) {
-				unifiedMessage = (Term) targetMember.getStateTransition().getMessageExpression();
-			}
-		}
-		return targetMember.getStateTransition().deriveNextStateExpressionFor(curOutputStateAccessor, unifiedMessage);
+		return resourcePaths;
 	}
 
-	private Term calcUnifiedMessage(ChannelMember targetMember, IResourceStateAccessor stateAccessor,
-			HashMap<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor)
+	private Term calcUnifiedMessage(ChannelMember targetMember, IResourceStateAccessor stateAccessor, 
+			Map<ChannelMember, IResourceStateAccessor> inputResourceToStateAccessor, Map<ChannelMember, Set<Position>> substitutedPositionsFromChannels)
 			throws InvalidMessage, ResolvingMultipleDefinitionIsFutureWork, UnificationFailed {
-		HashSet<Term> messageConstraints = new HashSet<>();
+		Set<Term> messageConstraints = new HashSet<>();
 		
 		// Calculate message constraints from input state transitions
 		for (ChannelMember inputMember: getInputChannelMembers()) {
@@ -299,7 +336,9 @@
 				curInputStateAccessor = inputResourceToStateAccessor.get(inputMember).getCurrentStateAccessorFor(inputMember, targetMember);
 				nextInputStateAccessor = inputResourceToStateAccessor.get(inputMember).getNextStateAccessorFor(inputMember, targetMember);
 			}
-			Expression messageConstraintByInput = inputMember.getStateTransition().deriveMessageConstraintFor(curInputStateAccessor, nextInputStateAccessor);
+			Set<Position> substitutedPositions = new HashSet<>();
+			Expression messageConstraintByInput = inputMember.getStateTransition().deriveMessageConstraintFor(curInputStateAccessor, nextInputStateAccessor, substitutedPositions);
+			if (substitutedPositions.size() > 0) substitutedPositionsFromChannels.put(inputMember, substitutedPositions);
 			messageConstraints.add((Term) messageConstraintByInput);
 		}
 
@@ -311,7 +350,9 @@
 			} else {
 				curInputStateAccessor = inputResourceToStateAccessor.get(referenceMember).getCurrentStateAccessorFor(referenceMember, targetMember);
 			}
-			Expression messageConstraintByReference = referenceMember.getStateTransition().deriveMessageConstraintFor(curInputStateAccessor);
+			Set<Position> substitutedPositions = new HashSet<>();
+			Expression messageConstraintByReference = referenceMember.getStateTransition().deriveMessageConstraintFor(curInputStateAccessor, substitutedPositions);
+			if (substitutedPositions.size() > 0) substitutedPositionsFromChannels.put(referenceMember, substitutedPositions);
 			messageConstraints.add((Term) messageConstraintByReference);
 		}
 
@@ -330,19 +371,19 @@
 		return unifiedMessage;
 	}
 
-	private ResourcePath fillOutsideResourcePath(ResourcePath resource, Term unifiedMessage, Expression messageTerm) 
+	private ResourcePath fillOutsideResourcePath(ResourcePath resource, Term unifiedMessage, Expression messageTerm, Set<Position> dependingVarPos) 
 			throws ResolvingMultipleDefinitionIsFutureWork {
 		ResourcePath filledResourcePath = new ResourcePath(resource);
 		
-		HashMap<Variable, Expression> bindings = new HashMap<>();
-		HashMap<Position, Variable> messageVars = messageTerm.getVariables();
+		Map<Variable, Entry<Position, Expression>> bindings = new HashMap<>();
+		Map<Position, Variable> messageVars = messageTerm.getVariables();
 		for (Entry<Position, Variable> messageVarEnt: messageVars.entrySet()) {
 			Variable var = messageVarEnt.getValue();
 			Position varPos = messageVarEnt.getKey();
 			Expression valueCalc = unifiedMessage.getSubTerm(varPos);
 			if (valueCalc != null) {
 				if (bindings.get(var) != null) throw new ResolvingMultipleDefinitionIsFutureWork();
-				bindings.put(var, valueCalc);
+				bindings.put(var, new AbstractMap.SimpleEntry(varPos, valueCalc));
 			}
 		}
 		
@@ -350,10 +391,15 @@
 		for (int i = 0; i < filledResourcePath.getPathParams().size(); i++) {
 			Expression pathParam = dstParams.get(i);
 			if (pathParam instanceof Variable) {
-				dstParams.set(i, bindings.get((Variable) pathParam));
+				dstParams.set(i, bindings.get((Variable) pathParam).getValue());
+				dependingVarPos.add(bindings.get((Variable) pathParam).getKey());
 			} else {
+				Map<Position, Variable> pathParamVars = ((Term) pathParam).getVariables();
 				for (Variable var: bindings.keySet()) {
-					pathParam = ((Term) pathParam).substitute(var, bindings.get(var));
+					if (pathParamVars.values().contains(var)) {
+						pathParam = ((Term) pathParam).substitute(var, bindings.get(var).getValue());
+						dependingVarPos.add(bindings.get((Variable) var).getKey());
+					}
 				}
 				if (!(pathParam instanceof Constant)) {
 					pathParam = ((Term) pathParam).reduce();