diff --git a/src/main/java/Input.java b/src/main/java/Input.java
index 80b66b6..4b8b0f9 100644
--- a/src/main/java/Input.java
+++ b/src/main/java/Input.java
@@ -7,7 +7,9 @@ class Example {
 class Example2 {
     boolean instVarBool;
     int m(int n){
-        if(instVarBool){
+        boolean localBool;
+        localBool = true;
+        if(localBool){
             return n;
         }
         return -1;
diff --git a/src/main/java/abstractSyntaxTree/Expression/IntConstantExpression.java b/src/main/java/abstractSyntaxTree/Expression/IntConstantExpression.java
index b1fd5de..b1a1d88 100644
--- a/src/main/java/abstractSyntaxTree/Expression/IntConstantExpression.java
+++ b/src/main/java/abstractSyntaxTree/Expression/IntConstantExpression.java
@@ -1,6 +1,12 @@
 package abstractSyntaxTree.Expression;
 
 import TypeCheck.AbstractType;
+import TypeCheck.TypeCheckResult;
+import abstractSyntaxTree.Parameter.ParameterList;
+import org.objectweb.asm.MethodVisitor;
+
+import java.util.HashMap;
+import java.util.LinkedHashMap;
 
 import java.util.Objects;
 
@@ -11,6 +17,16 @@ public class IntConstantExpression extends AbstractType implements IExpression{
         this.value = value;
     }
 
+    @Override
+    public TypeCheckResult typeCheck(HashMap<String, HashMap<String, HashMap<String, ParameterList>>> methodContext, HashMap<String, HashMap<String, String>> typeContext, HashMap<String, String> localVars) throws Exception {
+        return null;
+    }
+
+    @Override
+    public void codeGen(MethodVisitor mv, LinkedHashMap<String, String> localVars, HashMap<String, HashMap<String, String>> typeContext) throws Exception {
+
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
diff --git a/src/main/java/abstractSyntaxTree/Expression/LocalVarIdentifier.java b/src/main/java/abstractSyntaxTree/Expression/LocalVarIdentifier.java
index 141e318..2e3ceb9 100644
--- a/src/main/java/abstractSyntaxTree/Expression/LocalVarIdentifier.java
+++ b/src/main/java/abstractSyntaxTree/Expression/LocalVarIdentifier.java
@@ -25,7 +25,13 @@ public class LocalVarIdentifier implements IExpression{
 
     @Override
     public TypeCheckResult typeCheck(HashMap<String, HashMap<String, HashMap<String, ParameterList>>> methodContext, HashMap<String, HashMap<String, String>> typeContext, HashMap<String, String> localVars) throws Exception {
-        return null;
+       TypeCheckResult result = new TypeCheckResult();
+        if (localVars.containsKey(identifier)) {
+            result.type = localVars.get(identifier);
+        } else {
+            throw new Exception("TypeCheck Exception: local var does not exist");
+        }
+        return result;
     }
 
     @Override
diff --git a/src/main/java/abstractSyntaxTree/Statement/BlockStatement.java b/src/main/java/abstractSyntaxTree/Statement/BlockStatement.java
index 543d058..b573fbc 100644
--- a/src/main/java/abstractSyntaxTree/Statement/BlockStatement.java
+++ b/src/main/java/abstractSyntaxTree/Statement/BlockStatement.java
@@ -36,35 +36,38 @@ public class BlockStatement extends AbstractType implements IStatement {
         }
 
         for (IStatement statement : statements) {
-            TypeCheckResult typeOfCurrentStatement = statement.typeCheck(methodContext, typeContext, localVars);
+            // todo remove later if there are no null statement any more
+            if (statement != null) {
+                TypeCheckResult typeOfCurrentStatement = statement.typeCheck(methodContext, typeContext, localVars);
 
-            if (typeOfCurrentStatement.type.contains(",")) {
-                // else if has 2 returns, all code paths must retrun a value.
-                String[] substrings = typeOfCurrentStatement.type.split(",");
+                if (typeOfCurrentStatement.type.contains(",")) {
+                    // else if has 2 returns, all code paths must retrun a value.
+                    String[] substrings = typeOfCurrentStatement.type.split(",");
 
-                String firstType = substrings[0];
-                String secondType = substrings[1];
+                    String firstType = substrings[0];
+                    String secondType = substrings[1];
 
-                if(!firstType.equals(this.returnType) || !firstType.equals(this.returnType)){
-                    if(!firstType.equals("void")){
-                        throw new Exception("TypeCeck Exception: if paths return wrong type");
-                    }
-                    if(!secondType.equals("void")){
-                        throw new Exception("TypeCeck Exception: else paths return wrong type");
-                    }
-                    boolean firstIsVoid = firstType.equals("void");
+                    if (!firstType.equals(this.returnType) || !firstType.equals(this.returnType)) {
+                        if (!firstType.equals("void")) {
+                            throw new Exception("TypeCeck Exception: if paths return wrong type");
+                        }
+                        if (!secondType.equals("void")) {
+                            throw new Exception("TypeCeck Exception: else paths return wrong type");
+                        }
+                        boolean firstIsVoid = firstType.equals("void");
 
-                    if(!firstIsVoid){
-                        typeOfCurrentStatement.type = firstType;
-                    }else{
-                        typeOfCurrentStatement.type = secondType;
+                        if (!firstIsVoid) {
+                            typeOfCurrentStatement.type = firstType;
+                        } else {
+                            typeOfCurrentStatement.type = secondType;
+                        }
                     }
                 }
-            }
 
-            if (!typeOfCurrentStatement.type.equals(this.returnType)) {
-                if (!typeOfCurrentStatement.type.equals("void"))
-                    throw new Exception("TypeCheck Exception: Block returns the wrong type.");
+                if (!typeOfCurrentStatement.type.equals(this.returnType)) {
+                    if (!typeOfCurrentStatement.type.equals("void"))
+                        throw new Exception("TypeCheck Exception: Block returns the wrong type.");
+                }
             }
         }
         result.type = this.returnType;
diff --git a/src/main/java/astGenerator/ASTGenerator.java b/src/main/java/astGenerator/ASTGenerator.java
index b628494..8ae4d20 100644
--- a/src/main/java/astGenerator/ASTGenerator.java
+++ b/src/main/java/astGenerator/ASTGenerator.java
@@ -3,10 +3,7 @@ package astGenerator;
 import abstractSyntaxTree.Class.FieldDecl;
 import abstractSyntaxTree.Class.MethodDecl;
 import abstractSyntaxTree.Class.RefType;
-import abstractSyntaxTree.Expression.BinaryExpression;
-import abstractSyntaxTree.Expression.IExpression;
-import abstractSyntaxTree.Expression.IntConstantExpression;
-import abstractSyntaxTree.Expression.LocalVarIdentifier;
+import abstractSyntaxTree.Expression.*;
 import abstractSyntaxTree.Node;
 import abstractSyntaxTree.Parameter.Parameter;
 import abstractSyntaxTree.Parameter.ParameterList;
@@ -176,9 +173,12 @@ public class ASTGenerator extends DecafBaseVisitor<Node> {
 
     @Override
     public Node visitAssign(DecafParser.AssignContext ctx) {
-        return new AssignStatementExpression("", null, null);
+        Node right = visitExpression(ctx.expression());
+        Node left = visitAssignableExpr(ctx.assignableExpr());
+        return new AssignStatementExpression(ctx.Assign().getText(),(IExpression) left, (IExpression) right);
     }
 
+
     @Override
     public Node visitMethodCall(DecafParser.MethodCallContext ctx) {
         return super.visitMethodCall(ctx);
@@ -240,13 +240,14 @@ public class ASTGenerator extends DecafBaseVisitor<Node> {
     //todo
     @Override
     public Node visitDotSubExpr(DecafParser.DotSubExprContext ctx) {
-//        if (ctx.IntValue() != null) {
-//            int value = Integer.parseInt(ctx.IntValue().getText());
-//            return new IntConstantExpression(value);
-//        }
-        if(ctx.Identifier() != null) {
+        if (ctx.IntValue() != null) {
+            int value = Integer.parseInt(ctx.IntValue().getText());
+            return new IntConstantExpression(value);
+        } else if(ctx.Identifier() != null) {
             String identifier = ctx.Identifier().getText();
             return new LocalVarIdentifier(identifier);
+        } else if(ctx.instVar() != null) {
+            return visitInstVar(ctx.instVar());
         }
         return null;
     }
@@ -283,4 +284,20 @@ public class ASTGenerator extends DecafBaseVisitor<Node> {
         }
         return null;
     }
+
+    @Override
+    public Node visitInstVar(DecafParser.InstVarContext ctx) {
+        return super.visitInstVar(ctx);
+    }
+
+//    @Override
+//    public Node visitArgumentList(DecafParser.ArgumentListContext ctx) {
+//        if (ctx.expression().size() == 1) {
+//            return visitExpression(ctx.expression(0));
+//        } else if (ctx.expression().size() >= 2) {
+//            for(DecafParser.ExpressionContext expressionContext: ctx.expression()) {
+//
+//            }
+//        }
+//    }
 }