diff --git a/geosolver/geometric.py b/geosolver/geometric.py
index 10d0768..9c85c51 100644
--- a/geosolver/geometric.py
+++ b/geosolver/geometric.py
@@ -13,6 +13,7 @@ from notify import Notifier, Listener
 from tolerance import tol_eq
 from intersections import angle_3p, distance_2p
 from selconstr import SelectionConstraint
+from geosolver.intersections import is_left_handed, is_right_handed
 
 # ----------- GeometricProblem -------------
 
@@ -348,7 +349,7 @@ class GeometricSolver (Listener):
                                 parent.subs.append(map[inp])
         
         # combine clusters due to selection
-        if False:
+        if True:
             for method in self.dr.methods():
                 if isinstance(method, PrototypeMethod):
                     incluster = method.inputs()[0]
@@ -837,3 +838,26 @@ class RigidConstraint(ParametricConstraint):
         return "RigidConstraint("+str(self._variables)+")" 
 
 
+class RightHandedConstraint (SelectionConstraint):
+    """A selection constraint for 4 points to have a right-handed orientation"""
+    def __init__(self, v1, v2, v3, v4):
+        SelectionConstraint.__init__(self, is_right_handed, [v1,v2,v3,v4])
+
+
+class LeftHandedConstraint (SelectionConstraint):
+    """A selection constraint for 4 points to have a left-handed orientation"""
+    def __init__(self, v1, v2, v3, v4):
+        SelectionConstraint.__init__(self, is_left_handed, [v1,v2,v3,v4])
+
+class NotRightHandedConstraint (SelectionConstraint):
+    """A selection constraint for 4 points to not have a left-handed orientation, i.e. right-handed or in-plane"""
+    def __init__(self, v1, v2, v3, v4):
+        SelectionConstraint.__init__(self, fnot(is_right_handed), [v1,v2,v3,v4])
+
+class NotLeftHandedConstraint (SelectionConstraint):
+    """A selection constraint for 4 points to not have a left-handed orientation, i.e. right-handed or in-plane"""
+    def __init__(self, v1, v2, v3, v4):
+        SelectionConstraint.__init__(self, fnot(is_left_handed), [v1,v2,v3,v4])
+
+
+
diff --git a/test/test.py b/test/test.py
index 29b9125..1ebdd8d 100644
--- a/test/test.py
+++ b/test/test.py
@@ -6,7 +6,6 @@ from geosolver.vector import vector
 from geosolver.randomproblem import *
 from geosolver.diagnostic import diag_select, diag_print
 from geosolver.selconstr import fnot
-from geosolver.intersections import is_left_handed, is_right_handed
 import geosolver.tolerance as tolerance
 from time import time
 
@@ -481,8 +480,8 @@ def selection_problem():
     problem.add_constraint(DistanceConstraint('v2', 'v5', 10.0))
     problem.add_constraint(DistanceConstraint('v3', 'v5', 10.0))
 
-    problem.add_constraint(SelectionConstraint(is_left_handed, ['v1','v2','v3','v4']))
-    problem.add_constraint(SelectionConstraint(is_right_handed, ['v1','v2','v4','v5']))
+    #problem.add_constraint(SelectionConstraint(is_right_handed, ['v1','v2','v4','v5']))
+    problem.add_constraint(RightHandedConstraint('v1','v2','v4','v5'))
     
     return problem
 
@@ -742,9 +741,9 @@ def test(problem, use_prototype=True):
     print problem
     solver = GeometricSolver(problem, use_prototype)
     #solver.set_prototype_selection(use_prototype)
-    print "drplan:"
-    print solver.dr
-    print "number of top-level rigids:",len(solver.dr.top_level())
+    #print "drplan:"
+    #print solver.dr
+    #print "number of top-level rigids:",len(solver.dr.top_level())
     result = solver.get_result()
     print "result:"
     print result
@@ -885,21 +884,21 @@ def selection_test():
     print len(solver.get_solutions()), "solutions"
     
     # remove and add constraint
-    print "removing s1"
+    print "removing selection-constraint"
     problem.rem_constraint(s1)
 
     # solve again
     print len(solver.get_solutions()), "solutions"
 
     # remove and add constraint
-    print "adding s1"
+    print "re-adding selection constraint"
     problem.add_constraint(s1)
 
     # solve again
     print len(solver.get_solutions()), "solutions"
 
     # remove distance
-    print "removing and re-adding d15"
+    print "removing and re-adding distance v1-v5"
     problem.rem_constraint(problem.get_distance("v1","v5"))
     problem.add_constraint(DistanceConstraint('v1', 'v5', 10.0))