diff --git a/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/ConstantFolding.java b/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/ConstantFolding.java
new file mode 100644
index 00000000..597359a2
--- /dev/null
+++ b/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/ConstantFolding.java	
@@ -0,0 +1,511 @@
+/*
+ * To change this template, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package solution;
+import Triangle.AbstractSyntaxTrees.AnyTypeDenoter;
+import Triangle.AbstractSyntaxTrees.ArrayExpression;
+import Triangle.AbstractSyntaxTrees.ArrayTypeDenoter;
+import Triangle.AbstractSyntaxTrees.AssignCommand;
+import Triangle.AbstractSyntaxTrees.BinaryExpression;
+import Triangle.AbstractSyntaxTrees.BinaryOperatorDeclaration;
+import Triangle.AbstractSyntaxTrees.BoolTypeDenoter;
+import Triangle.AbstractSyntaxTrees.CallCommand;
+import Triangle.AbstractSyntaxTrees.CallExpression;
+import Triangle.AbstractSyntaxTrees.CharTypeDenoter;
+import Triangle.AbstractSyntaxTrees.CharacterExpression;
+import Triangle.AbstractSyntaxTrees.CharacterLiteral;
+import Triangle.AbstractSyntaxTrees.ConstActualParameter;
+import Triangle.AbstractSyntaxTrees.ConstDeclaration;
+import Triangle.AbstractSyntaxTrees.ConstFormalParameter;
+import Triangle.AbstractSyntaxTrees.DotVname;
+import Triangle.AbstractSyntaxTrees.EmptyActualParameterSequence;
+import Triangle.AbstractSyntaxTrees.EmptyCommand;
+import Triangle.AbstractSyntaxTrees.EmptyExpression;
+import Triangle.AbstractSyntaxTrees.EmptyFormalParameterSequence;
+import Triangle.AbstractSyntaxTrees.ErrorTypeDenoter;
+import Triangle.AbstractSyntaxTrees.Expression;
+import Triangle.AbstractSyntaxTrees.FuncActualParameter;
+import Triangle.AbstractSyntaxTrees.FuncDeclaration;
+import Triangle.AbstractSyntaxTrees.FuncFormalParameter;
+import Triangle.AbstractSyntaxTrees.Identifier;
+import Triangle.AbstractSyntaxTrees.IfCommand;
+import Triangle.AbstractSyntaxTrees.IfExpression;
+import Triangle.AbstractSyntaxTrees.IntTypeDenoter;
+import Triangle.AbstractSyntaxTrees.IntegerExpression;
+import Triangle.AbstractSyntaxTrees.IntegerLiteral;
+import Triangle.AbstractSyntaxTrees.LetCommand;
+import Triangle.AbstractSyntaxTrees.LetExpression;
+import Triangle.AbstractSyntaxTrees.MultipleActualParameterSequence;
+import Triangle.AbstractSyntaxTrees.MultipleArrayAggregate;
+import Triangle.AbstractSyntaxTrees.MultipleFieldTypeDenoter;
+import Triangle.AbstractSyntaxTrees.MultipleFormalParameterSequence;
+import Triangle.AbstractSyntaxTrees.MultipleRecordAggregate;
+import Triangle.AbstractSyntaxTrees.Operator;
+import Triangle.AbstractSyntaxTrees.ProcActualParameter;
+import Triangle.AbstractSyntaxTrees.ProcDeclaration;
+import Triangle.AbstractSyntaxTrees.ProcFormalParameter;
+import Triangle.AbstractSyntaxTrees.Program;
+import Triangle.AbstractSyntaxTrees.RecordExpression;
+import Triangle.AbstractSyntaxTrees.RecordTypeDenoter;
+import Triangle.AbstractSyntaxTrees.SequentialCommand;
+import Triangle.AbstractSyntaxTrees.SequentialDeclaration;
+import Triangle.AbstractSyntaxTrees.SimpleTypeDenoter;
+import Triangle.AbstractSyntaxTrees.SimpleVname;
+import Triangle.AbstractSyntaxTrees.SingleActualParameterSequence;
+import Triangle.AbstractSyntaxTrees.SingleArrayAggregate;
+import Triangle.AbstractSyntaxTrees.SingleFieldTypeDenoter;
+import Triangle.AbstractSyntaxTrees.SingleFormalParameterSequence;
+import Triangle.AbstractSyntaxTrees.SingleRecordAggregate;
+import Triangle.AbstractSyntaxTrees.SubscriptVname;
+import Triangle.AbstractSyntaxTrees.TypeDeclaration;
+import Triangle.AbstractSyntaxTrees.UnaryExpression;
+import Triangle.AbstractSyntaxTrees.UnaryOperatorDeclaration;
+import Triangle.AbstractSyntaxTrees.VarActualParameter;
+import Triangle.AbstractSyntaxTrees.VarDeclaration;
+import Triangle.AbstractSyntaxTrees.VarFormalParameter;
+import Triangle.AbstractSyntaxTrees.Visitor;
+import Triangle.AbstractSyntaxTrees.VnameExpression;
+import Triangle.AbstractSyntaxTrees.WhileCommand;
+import Triangle.StdEnvironment;
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+/**
+ *
+ * @author Michael
+ */
+public class ConstantFolding implements Visitor{
+    
+    
+    
+         /**
+	 * Returns <code>true</code> if the given expression represents constant value.
+	 * This value can be a boolean or integer.
+	 * @param e the expression to test
+	 * @return <code>true</code> if the given expression represents constant value
+	 */
+	private boolean isConstant(Expression e) {
+		if(e instanceof IntegerExpression)
+			return true;
+		if(e instanceof VnameExpression) {
+			VnameExpression vname = (VnameExpression)e;
+			if(vname.V instanceof SimpleVname)
+				if(((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.trueDecl.I.spelling) 
+						|| ((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.falseDecl.I.spelling))
+					return true;
+		}
+		return false;
+	}
+	
+	/**
+	 * Returns the boolean value of the given expression that represents a boolean value.
+	 * @param e a boolean value
+	 * @return the boolean value of the given expression that represents a boolean value
+	 */
+	private boolean parseBoolean(Expression e) {
+		if(e instanceof VnameExpression) {
+			VnameExpression vname = (VnameExpression)e;
+			if(vname.V instanceof SimpleVname)
+				if(((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.trueDecl.I.spelling))
+					return true;
+				if(((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.falseDecl.I.spelling))
+					return false;
+		}
+		throw new RuntimeException();
+	}
+	
+	/**
+	 * Returns an expression representing the given boolean value.
+	 * @param val the boolean value that will be represented by the returned expression
+	 * @return an expression representing the given boolean value
+	 */
+	private Expression createBoolean(boolean val) {
+		Identifier iAST = new Identifier(val ? "true" : "false", new SourcePosition());
+		iAST.decl = val ? StdEnvironment.trueDecl : StdEnvironment.falseDecl;
+		SimpleVname vAST = new SimpleVname(iAST, new SourcePosition());
+		vAST.type = StdEnvironment.booleanType;
+		VnameExpression boolExpression = new VnameExpression(vAST, new SourcePosition());
+		return boolExpression;
+	}
+
+        
+       
+    @Override
+    public Object visitBinaryExpression(BinaryExpression ast, Object o) {
+        
+        boolean e1 = false;
+        boolean e2 = false;
+        if(isConstant(ast.E1)){
+            //optimize E
+            try{
+                boolean b = parseBoolean(ast.E1);
+                ast.E1.value = createBoolean(b);
+                ast.E1.type = boolean;
+
+
+            } catch (RuntimeException e)
+            {
+                ast.E1.type = integer;
+             
+            }
+            e1 = true;
+        }
+
+        if(isConstant(ast.E2)){
+            //optimize E
+            try{
+                boolean b = parseBoolean(ast.E2);
+                ast.E2.value = createBoolean(b);
+                ast.E2.type = boolean;
+
+
+            } catch (RuntimeException e)
+            {
+                ast.E2.type = integer;
+
+            }
+            e2 = true;
+        }
+
+        if(e1 & e2) {
+            return new ConstExpression(ast.O(ast.E1, ast.E2));
+        }
+
+        return ast;
+        
+    }
+
+    @Override
+    public Object visitUnaryExpression(UnaryExpression ast, Object o) {
+        if(isConstant(ast.E)){
+            //optimize E
+            try{
+                boolean b = parseBoolean(ast.E);
+                ast.E.value = createBoolean(b);
+                ast.E.type = boolean;
+                //optimize operator
+                ast.E.value = ast.O(b);
+               
+
+
+            } catch (RuntimeException e)
+            {
+                ast.E.type = integer;
+                //optimize operator
+                ast.E.value = ast.O((Integer) ast.E.value);
+            }
+
+
+            return ast;
+        }
+    }
+
+
+
+
+
+    
+    @Overridev
+    public Object visitBinaryOperatorDeclaration(BinaryOperatorDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitUnaryOperatorDeclaration(UnaryOperatorDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+
+    
+        
+    @Override
+    public Object visitAssignCommand(AssignCommand ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitCallCommand(CallCommand ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitEmptyCommand(EmptyCommand ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitIfCommand(IfCommand ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitLetCommand(LetCommand ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSequentialCommand(SequentialCommand ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitWhileCommand(WhileCommand ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitArrayExpression(ArrayExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitCallExpression(CallExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitCharacterExpression(CharacterExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitEmptyExpression(EmptyExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitIfExpression(IfExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitIntegerExpression(IntegerExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitLetExpression(LetExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitRecordExpression(RecordExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitVnameExpression(VnameExpression ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitConstDeclaration(ConstDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitFuncDeclaration(FuncDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitProcDeclaration(ProcDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSequentialDeclaration(SequentialDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitTypeDeclaration(TypeDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitVarDeclaration(VarDeclaration ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitMultipleArrayAggregate(MultipleArrayAggregate ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSingleArrayAggregate(SingleArrayAggregate ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitMultipleRecordAggregate(MultipleRecordAggregate ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSingleRecordAggregate(SingleRecordAggregate ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitConstFormalParameter(ConstFormalParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitFuncFormalParameter(FuncFormalParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitProcFormalParameter(ProcFormalParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitVarFormalParameter(VarFormalParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitEmptyFormalParameterSequence(EmptyFormalParameterSequence ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitMultipleFormalParameterSequence(MultipleFormalParameterSequence ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSingleFormalParameterSequence(SingleFormalParameterSequence ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitConstActualParameter(ConstActualParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitFuncActualParameter(FuncActualParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitProcActualParameter(ProcActualParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitVarActualParameter(VarActualParameter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitEmptyActualParameterSequence(EmptyActualParameterSequence ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitMultipleActualParameterSequence(MultipleActualParameterSequence ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSingleActualParameterSequence(SingleActualParameterSequence ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitAnyTypeDenoter(AnyTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitArrayTypeDenoter(ArrayTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitBoolTypeDenoter(BoolTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitCharTypeDenoter(CharTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitErrorTypeDenoter(ErrorTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSimpleTypeDenoter(SimpleTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitIntTypeDenoter(IntTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitRecordTypeDenoter(RecordTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitMultipleFieldTypeDenoter(MultipleFieldTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSingleFieldTypeDenoter(SingleFieldTypeDenoter ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitCharacterLiteral(CharacterLiteral ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitIdentifier(Identifier ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitIntegerLiteral(IntegerLiteral ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitOperator(Operator ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitDotVname(DotVname ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSimpleVname(SimpleVname ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitSubscriptVname(SubscriptVname ast, Object o) {
+        return null; // not of interest
+    }
+
+    @Override
+    public Object visitProgram(Program ast, Object o) {
+        return null; // not of interest
+    }
+    
+}
diff --git a/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/constant_folding_helper_functions.java b/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/constant_folding_helper_functions.java
deleted file mode 100644
index 5db56e5e..00000000
--- a/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/constant_folding_helper_functions.java	
+++ /dev/null
@@ -1,49 +0,0 @@
-	/**
-	 * Returns <code>true</code> if the given expression represents constant value.
-	 * This value can be a boolean or integer.
-	 * @param e the expression to test
-	 * @return <code>true</code> if the given expression represents constant value
-	 */
-	private boolean isConstant(Expression e) {
-		if(e instanceof IntegerExpression)
-			return true;
-		if(e instanceof VnameExpression) {
-			VnameExpression vname = (VnameExpression)e;
-			if(vname.V instanceof SimpleVname)
-				if(((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.trueDecl.I.spelling) 
-						|| ((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.falseDecl.I.spelling))
-					return true;
-		}
-		return false;
-	}
-	
-	/**
-	 * Returns the boolean value of the given expression that represents a boolean value.
-	 * @param e a boolean value
-	 * @return the boolean value of the given expression that represents a boolean value
-	 */
-	private boolean parseBoolean(Expression e) {
-		if(e instanceof VnameExpression) {
-			VnameExpression vname = (VnameExpression)e;
-			if(vname.V instanceof SimpleVname)
-				if(((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.trueDecl.I.spelling))
-					return true;
-				if(((SimpleVname)vname.V).I.spelling.equals(StdEnvironment.falseDecl.I.spelling))
-					return false;
-		}
-		throw new RuntimeException();
-	}
-	
-	/**
-	 * Returns an expression representing the given boolean value.
-	 * @param val the boolean value that will be represented by the returned expression
-	 * @return an expression representing the given boolean value
-	 */
-	private Expression createBoolean(boolean val) {
-		Identifier iAST = new Identifier(val ? "true" : "false", new SourcePosition());
-		iAST.decl = val ? StdEnvironment.trueDecl : StdEnvironment.falseDecl;
-		SimpleVname vAST = new SimpleVname(iAST, new SourcePosition());
-		vAST.type = StdEnvironment.booleanType;
-		VnameExpression boolExpression = new VnameExpression(vAST, new SourcePosition());
-		return boolExpression;
-	}