diff --git a/JAPL/parser.py b/JAPL/parser.py
index 8fbf408..f808b1d 100644
--- a/JAPL/parser.py
+++ b/JAPL/parser.py
@@ -401,7 +401,10 @@ class Parser(object):
             while True:
                 if len(parameters) >= 255:
                     raise self.throw(self.peek(), "Cannot have more than 255 arguments")
-                parameters.append(self.consume(TokenType.ID, "Expecting parameter name"))
+                parameter = self.consume(TokenType.ID, "Expecting parameter name")
+                if parameter in parameters:
+                    raise self.throw(self.peek(), "Multiple parameters with the same name in function declaration are not allowed")
+                parameters.append(parameter)
                 if not self.match(TokenType.COMMA):
                     break
         self.consume(TokenType.RP, "Unexpected error while parsing function declaration")
diff --git a/JAPL/types/japlclass.py b/JAPL/types/japlclass.py
index dbd9a80..7e51104 100644
--- a/JAPL/types/japlclass.py
+++ b/JAPL/types/japlclass.py
@@ -17,8 +17,11 @@ class JAPLClass(Callable):
     def get_method(self, name: str):
         if name in self.methods:
             return self.methods[name]
-        elif self.superclass and name in self.superclass.methods:
-            return self.superclass.methods[name]
+        superclass = self.superclass
+        while superclass:
+            if name in superclass.methods:
+                return superclass.methods[name]
+            superclass = superclass.superclass
 
     def __repr__(self):
         return f"<class '{self.name}'>"
diff --git a/examples/fib.jpl b/examples/fib.jpl
index 57c3018..0a97934 100644
--- a/examples/fib.jpl
+++ b/examples/fib.jpl
@@ -5,6 +5,8 @@ fun fib(n) {
   return fib(n - 2) + fib(n - 1);
 }
 
-for (var i = 0; i < 20; i = i + 1) {
-  print fib(i);
-}
+
+var start = clock();
+fib(30);
+var end = clock() - start;
+print(end);
diff --git a/nimjapl/interpreter.nim b/nimjapl/interpreter.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/lexer.nim b/nimjapl/lexer.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/meta/classtype.nim b/nimjapl/meta/classtype.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/meta/expression.nim b/nimjapl/meta/expression.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/meta/functiontype.nim b/nimjapl/meta/functiontype.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/meta/statement.nim b/nimjapl/meta/statement.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/meta/tokentype.nim b/nimjapl/meta/tokentype.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/parser.nim b/nimjapl/parser.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/types/callable.nim b/nimjapl/types/callable.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/types/class.nim b/nimjapl/types/class.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/types/function.nim b/nimjapl/types/function.nim
new file mode 100644
index 0000000..e69de29
diff --git a/nimjapl/types/instance.nim b/nimjapl/types/instance.nim
new file mode 100644
index 0000000..e69de29