diff --git a/abacus_core.py b/abacus_core.py
index 47a3429..f108d3f 100644
--- a/abacus_core.py
+++ b/abacus_core.py
@@ -13,6 +13,9 @@ class AbacusCore:
         self._vars['alpha'] = 1
         self._vars['beta'] = 2
 
+        self._operators = ['+', '-', '/', '*']
+        self._delimiters = ['(', ')', '[', ']', ';', ' ']
+
     def get_vars(self):
         return self._vars
 
@@ -40,41 +43,65 @@ class AbacusCore:
         :param input_str:
         :return:
         '''
-        if len(input_str) < 1:
+        comment = None
+        orig_input_str = input_str
+        if len(input_str) < 1:  # leere eingabe wird nicht akzeptiert
             return
-        if input_str.find(':')>-1:
-            chunks = input_str.split('#')
-            comment = None
-            if len(chunks) > 1:
-                comment = chunks[1]
-                input_str = chunks[0]
-            inp_chunks = input_str.split(':')
-            if len(inp_chunks) == 2:
-                self._funcs[inp_chunks[0]] = inp_chunks[1]
-                return inp_chunks[0], inp_chunks[1], 0, comment
-        else:
-            return self._with_variable(input_str)
+        chunks = input_str.split('#')
+        if len(chunks) > 1:
+            input_str = chunks[0]
+            comment = ' '.join(chunks[1:])
+        chunks = input_str.split('=')  # gibt es variablenzuweisung?
+        if len(chunks) > 2:
+            raise ValueError('Mehrfachzuweisung wird nicht unterstützt')
+        elif len(chunks) > 1:
+            expression = self._with_variable_another_way(chunks[1])
+            self._vars[chunks[0]] = expression
+            return
+        chunks = input_str.split(':')  # gibt es funktionsdefinition?
+        if len(chunks) > 1:
+            self._funcs[chunks[0]] = chunks[1]
+            return
+        res = self._with_variable_another_way(input_str)
+        self._vars['result'] = res
+        return orig_input_str, None, res, comment
 
-    def _with_variable(self, input_str):
+
+
+
+    def _with_variable_another_way(self, input_str):
         input_str, comment = self._get_input_wo_commentar(input_str)
-        func = self._funcs.get(input_str)
-        if func:
-            input_str = func
         input_str = ''.join(input_str.split())  # entferne alle leerzeichen
         input_str = input_str.replace(',', '.')
-        if input_str is not None:
-            expression, new_var = self._is_new_variable(input_str)  # chunks für variablenzuweisung
-            # print('expression', expression)
-            expression_wo_vars = self._replace_vars(expression)
-            # print('expression wo vars', expression_wo_vars)
-            expression_calculated = self._calculate(expression_wo_vars)
-            # print('eval', expression_calculated)
-            if new_var is not None:
-                self._vars[new_var] = expression_calculated
-            self._vars['result'] = expression_calculated
-            return input_str, expression_wo_vars, expression_calculated, comment
+        opdel = self._operators + self._delimiters
+        chunks = list()
+        last_index = 0
+        for i, v in enumerate(input_str):
+            if v in opdel:
+                chunk = input_str[last_index:i]
+                chunk = self._is_a_variable_or_func(chunk)
+                chunks.append(chunk)
+                chunks.append(input_str[i])
+                last_index = i+1
+            elif i == len(input_str)-1:
+                chunk = input_str[last_index:i+1]
+                chunk = self._is_a_variable_or_func(chunk)
+                chunks.append(chunk)
+        return eval(''.join(chunks))
+
+    def _is_a_variable_or_func(self, chunk):
+        var = self._vars.get(chunk)
+        if not var:
+            var = self._funcs.get(chunk)
+            if var:
+                var = self._with_variable_another_way(var)
+        if var:
+            return str(var)
         else:
-            return 'comment', comment
+            return chunk
+
+
+
 
     def _replace_vars(self, input_str):
         '''
@@ -84,10 +111,8 @@ class AbacusCore:
         '''
         first_position = None
         new_input_str = ''
-        operators = ['+', '-', '/', '*']
-        delimiters = ['(', ')', '[', ']', ';', ' ']
-        op_del = operators + delimiters
-        if input_str[0] in operators:
+        op_del = self._operators + self._delimiters
+        if input_str[0] in self._operators:
             input_str = 'result' + input_str
         input_str_len = len(input_str)
         for i, c in enumerate(input_str):
diff --git a/main.py b/main.py
index afb1efd..14b34de 100644
--- a/main.py
+++ b/main.py
@@ -48,7 +48,8 @@ class AbacusGUI:
             input_wo_var = str(result[1])
             ergebnis = str(result[2])
             comment = result[3]
-            res_str = str(self._step) + '. ' + input_str + ' => ' + input_wo_var + ' = ' + ergebnis
+            res_str = str(self._step) + '. ' + input_str + ' = ' + ergebnis
+            # res_str = str(self._step) + '. ' + input_str + ' => ' + input_wo_var + ' = ' + ergebnis
             if comment:
                 res_str += ' ' + comment
             item = QStandardItem(res_str)