diff --git a/Uebung-01/MaMa.py b/Uebung-01/MaMa.py
index 930b497..f558f14 100644
--- a/Uebung-01/MaMa.py
+++ b/Uebung-01/MaMa.py
@@ -41,13 +41,20 @@ class MaMa:
 
     # Decodes string MaMa instructions to function callables
     @staticmethod
-    def decode(micro: str) -> Tuple[str, Optional[List[int]]]:
+    def decode(micro: str) -> Tuple[str, Optional[List[Any]]]:
         if "(" in micro:
             name, rest = micro.split("(", 1)
-            args_str = rest[:-1]
-            if args_str.strip() == "":
+            args_str = rest[:-1].strip()
+            if args_str == "":
                 return name, []
-            args = [int(a.strip()) for a in args_str.split(",")]
+            args = []
+            for a in args_str.split(","):
+                a = a.strip()
+                try:
+                    a = int(a)
+                except ValueError:
+                    pass  # keep symbolic argument (e.g., 'n')
+                args.append(a)
             return name, args
         return micro, None
 
diff --git a/Uebung-01/MaMaMa.py b/Uebung-01/MaMaMa.py
index 7a9c818..e661e32 100644
--- a/Uebung-01/MaMaMa.py
+++ b/Uebung-01/MaMaMa.py
@@ -26,17 +26,29 @@ class MaMaMa(MaMa):
 
     # Flatten macros recursively
     def __flatten_macro(self) -> None:
-        def expand(prog: Dict[int, str], stack: List[str]) -> List[Tuple[str, List[str]]]:
+        def expand(prog: Dict[int, str], stack: List[str], env: Dict[str, Any]) -> List[Tuple[str, List[str]]]:
             out: List[Tuple[str, List[str]]] = []
             for _, micro in sorted(prog.items()):
                 name, args = self.decode(micro)
+
+                # substitute arguments if defined in env
+                if args:
+                    args = [env.get(str(a), a) for a in args]
+                    micro = f"{name}({','.join(map(str, args))})"
+
                 if name in self.macros:
-                    out.extend(expand(self.macros[name]["prog"], stack + [name]))
+                    macro = self.macros[name]
+                    params = macro.get("args") or []
+                    new_env = env.copy()
+                    if args and params:
+                        for p, v in zip(params, args):
+                            new_env[p] = v
+                    out.extend(expand(macro["prog"], stack + [name], new_env))
                 else:
                     out.append((micro, list(stack)))
             return out
 
-        expanded = expand(self.prog, [])
+        expanded = expand(self.prog, [], {})
         self.prog = {i: call for i, (call, _) in enumerate(expanded)}
         self._macro_trace = {i: macros for i, (_, macros) in enumerate(expanded)}
 
diff --git a/Uebung-01/ggt.py b/Uebung-01/ggt.py
index 14c94e3..fb2faa9 100644
--- a/Uebung-01/ggt.py
+++ b/Uebung-01/ggt.py
@@ -14,7 +14,7 @@ if __name__ == "__main__":
         8: 'leq(14)',
         9: 'ldo(-1)',
         10: 'ldo(-1)',
-        11: 'subs',
+        11: 'sub',
         12: 'sto(-2)',
         13: 'ujp(6)',
         14: 'ldo(-1)',
@@ -27,11 +27,12 @@ if __name__ == "__main__":
     }
 
     # Create and execute MaMa instance
-    machine = MaMaMa(prog, [4, 6])
+    machine = MaMaMa(['equal0(3)', 'stop', 'push(10)', 'stop'], [4, 6, 0])
 
-    machine.add_macro('subs', {
-        0: "sub",
-    })
+    machine.add_macro('equal0', [
+        'push(0)',
+        'equal(n)'
+    ], ["n"])
 
     # Visualize finished execution using journal
     gui = MaMaGUI(machine)