diff --git a/src/dbms.py b/src/dbms.py
diff --git a/src/graph_algorithms.py b/src/graph_algorithms.py
diff --git a/src/interpreter.py b/src/interpreter.py
@@ -170,126 +170,3 @@ def iterate(values, do_widen = True):
                           iterations > iterations_without_widening)
             iterations += 1
 
-if __name__ == '__main__':
-
-    boxes_factory = boxes.BoxDomainFactory(-128, 128)
-
-    # example bounds001.c
-
-    boxes_factory.add_var('index', -65536, 65536)
-    boxes_factory.add_var('length', -65536, 65536)
-    boxes_factory.add_var('access', -65536, 65536)
-
-    def bounds_001():
-
-        cfg = Method_CFG(1, 5)
-        cfg.add_control_loc(2)
-        cfg.add_control_loc(3)
-        cfg.add_control_loc(4)
-
-        cfg.set_edge(1, 2, None, [['length', [5]], ['access', [0]]])
-        cfg.set_edge(2, 3,
-                     ['>','index', 'length'],
-                     [])
-        cfg.set_edge(3, 5,
-                     None,
-                     [['access', [ '-', 'index', 'length']]])
-
-        cfg.set_edge(2, 4,
-                     ['<=','index', 'length'],
-                     [])
-        cfg.set_edge(4, 5,
-                     None,
-                     [['access', ['index']]])
-
-        print cfg.to_string()
-
-        cfg.forward_analyze(boxes_factory, boxes_factory.get_top(), boxes_factory.get_bot())
-
-
-    def bounds_002():
-
-        cfg = Method_CFG(1, 5)
-        cfg.add_control_loc(2)
-        cfg.add_control_loc(3)
-        cfg.add_control_loc(4)
-
-        cfg.set_edge(1, 2, None, [['length', [5]], ['access', [0]]])
-        cfg.set_edge(2, 3,
-                     ['>','index', 'length'],
-                     [])
-        cfg.set_edge(3, 5,
-                     None,
-                     [['access', [ '-', 'length', 1]]])
-
-        cfg.set_edge(2, 4,
-                     ['<=','index', 'length'],
-                     [])
-        cfg.set_edge(4, 5,
-                     None,
-                     [['access', ['index']]])
-
-        print cfg.to_string()
-        cfg.forward_analyze(boxes_factory, boxes_factory.get_top(), boxes_factory.get_bot())
-
-
-    def bounds_003():
-
-        cfg = Method_CFG(1, 6)
-        cfg.add_control_loc(2)
-        cfg.add_control_loc(3)
-        cfg.add_control_loc(4)
-        cfg.add_control_loc(5)
-
-        cfg.set_edge(1, 2, None, [['length', [5]], ['access', [0]]])
-        cfg.set_edge(2, 4,
-                     ['>','index', 'length'],
-                     [])
-        cfg.set_edge(2, 3,
-                     ['<=','index', 'length'],
-                     [])
-        cfg.set_edge(3, 4,
-                     ['<','index', 0],
-                     [])
-        cfg.set_edge(3, 5,
-                     ['>=','index', 0],
-                     [])
-
-        cfg.set_edge(4, 6,
-                     None,
-                     [['access', [ '-', 'length', 1]]])
-
-        cfg.set_edge(5, 6,
-                     None,
-                     [['access', ['index']]])
-
-
-        print cfg.to_string()
-        cfg.forward_analyze(boxes_factory, boxes_factory.get_top(), boxes_factory.get_bot())
-
-
-    def bounds_004():
-
-        cfg = Method_CFG(1, 3)
-        cfg.add_control_loc(2)
-
-        cfg.set_edge(1, 2, None, [['length', [5]], ['access', [0]]])
-        cfg.set_edge(2, 3,
-                     None,
-                     [['index', [ '%', 'index', 2]]])
-
-        print cfg.to_string()
-        cfg.forward_analyze(boxes_factory, boxes_factory.get_top(), boxes_factory.get_bot())
-
-    print "BOUNDS 001"
-    bounds_001()
-
-    print "BOUNDS 002"
-    bounds_002()
-
-    print "BOUNDS 003"
-    bounds_003()
-
-    print "BOUNDS 004"
-    bounds_004()
-
diff --git a/src/simple_analyzer.py b/src/simple_analyzer.py
@@ -8,8 +8,6 @@
 ##############################
 
 
-import boxes
-
 # (I) Arithmetic expressions
 # 
 # CONST
@@ -24,7 +22,6 @@
 #
 # No nested expressions supported yet.
 
-
 #
 # (II) Assignments
 #
@@ -45,7 +42,7 @@
 # ['<=', 'x', 'y']
 
 
-class Method_CFG():
+class MethodCFG():
 
     def __init__(self, init_location, end_location):
         self.control_locs = [init_location, end_location]
@@ -56,7 +53,6 @@ def __init__(self, init_location, end_location):
 
     def to_string(self):
         result = ''
-
         for (s, t) in self.edges:
             (cond, actions) = self.edges[(s, t)]
             result += '%s -> %s \n\t' % (s, t)
@@ -97,7 +93,7 @@ def apply_assignment(assignment, value):
                 return dom.op_binary(value,
                                      '+',
                                      variable,
-                                     expression[0],
+                                     op1,
                                      0)
             elif len(expression) == 3:
                 (operator, op1, op2) = expression

diff --git a/test/test_dbm.py b/test/test_dbm.py
@@ -1,11 +1,10 @@
 import pytest
 
-import graph_algorithms
-import dbms
+import dbm
 
 def test_dbm_set_weight_get_weight():
 
-    d = dbms.DBM()
+    d = dbm.DBM()
     d.set_weight(1, 3, 2)
     assert d.get_weight(1, 2) == 3
     d.set_weight(2, 4, 2)
@@ -27,7 +26,7 @@ def test_dbm_set_weight_get_weight():
 
 def test_dbm_copy():
 
-    d = dbms.DBM()
+    d = dbm.DBM()
     x = [1,2]
     y = [3,4]
     d.set_weight(1, x , 2)
@@ -37,15 +36,15 @@ def test_dbm_copy():
 
 def test_dbm_exists_negative_cycle():
 
-    d1 = dbms.DBM()
+    d1 = dbm.DBM()
     d1.set_weight(1, 1, 2)
     d1.set_weight(2, -2, 1)
     assert d1.exists_negative_cycle()
-    d2 = dbms.DBM()
+    d2 = dbm.DBM()
     d2.set_weight(1, -2, 2)
     d2.set_weight(2, 3, 1)
     assert not d2.exists_negative_cycle()
-    d3 = dbms.DBM()
+    d3 = dbm.DBM()
     for i in range(0, 500):
         d3.set_weight(i, i*((-1)**(i % 2)), i+1)
     d3.set_weight(500, 100, 50)
@@ -56,7 +55,7 @@ def test_dbm_exists_negative_cycle():
 def test_dbm_find_shortest_paths():
 
     # example from wikipedia, slightly extended
-    d1 = dbms.DBM()
+    d1 = dbm.DBM()
     d1.set_weight(1, -2, 3)
     d1.set_weight(3, 2, 4)
     d1.set_weight(4, -1, 2)

diff --git a/test/test_dbms.py b/test/test_dbms.py
@@ -5,17 +5,16 @@
 
 def test_dbms_conditions_intersect_1():
     factory = dbms.DBMFactory(-512, 512)
-    factory.add_var(0, 0, 0)
-    factory.add_var('x', -512, 512)
-    factory.add_var('y', -512, 512)
-    factory.add_var('z', -512, 512)
+    factory.add_integer_var(0, 0, 0)
+    factory.add_integer_var('x', -512, 512)
+    factory.add_integer_var('y', -512, 512)
+    factory.add_integer_var('z', -512, 512)
 
     e1 = factory.get_top()
     e2 = factory.get_top()
     e3 = factory.get_top()
     e4 = factory.get_top()
 
-
     # e1: x = y && z > x
     e1 = factory.cond_binary(e1, '==', 'x', 'y')
     e1 = factory.cond_binary(e1, '>', 'z', 'x')
@@ -47,27 +46,24 @@ def test_dbms_conditions_intersect_1():
 def test_dbms_operations_1():
 
     factory = dbms.DBMFactory(-512, 512)
-    factory.add_var(0, 0, 0)
-    factory.add_var('x', -512, 512)
-    factory.add_var('y', -512, 512)
-    factory.add_var('z', -512, 512)
+    factory.add_integer_var(0, 0, 0)
+    factory.add_integer_var('x', -512, 512)
+    factory.add_integer_var('y', -512, 512)
+    factory.add_integer_var('z', -512, 512)
 
     e1 = factory.get_top()
     e2 = factory.get_top()
-    e3 = factory.get_top()
-    e4 = factory.get_top()
 
-    # e1: x > y
-
+    # e1 := x > y
     e1 = factory.cond_binary(e1, '>', 'x', 'y')
 
-    # z = x
+    # e1 := e1 and z = x
     e1 = factory.op_binary(e1, '+', 'z', 'x', 0)
+    print factory.to_string(factory._normalize(e1))
 
     # now: z < y should be impossible
     e2 = factory.cond_binary(e1, '<', 'z', 'y')
-
-    assert factory.is_eq(e2,
-                         factory.get_bot())
+    print factory.to_string(factory._normalize(e2))
+    assert factory.is_eq(e2, factory.get_bot())
 
 
diff --git a/test_programs/dbm_1.c b/test_programs/dbm_1.c
@@ -2,9 +2,5 @@ int main()
 {
   int x;
   int y;
-  if (x > y)
-    {
-      if (x < y)
-	{ x = 1000; }
-    }
+  x = y % 10;
 }