diff --git a/test_synth.py b/test_synth.py
index c5055db..7f496e9 100644
--- a/test_synth.py
+++ b/test_synth.py
@@ -10,20 +10,32 @@ oo = float('inf')
 ex1 = ("A > a?", ("a?",), {"a?": (0, 10)}, {"a?": False}, {"a?": 1})
 ex2 = ("F[0, b?](A > a?)", ("a?", "b?"), {"a?": (0, 10), "b?": (0, 5)},
        {"a?": False, "b?": True}, {"a?": 4, "b?": 0.2})
+ex3 = ("F[0, b?](A < 0)", ("b?",), {"b?": (0, 5)},
+       {"b?": True}, {"b?": 5})
+ex4 = ("G[0, b?](A < 0)", ("b?",), {"b?": (0.1, 5)},
+       {"b?": True}, {"b?": 0.1})
+ex5 = ("F[0, b?](A > 0)", ("b?",), {"b?": (0.1, 5)},
+       {"b?": True}, {"b?": 0.1})
 x = pd.DataFrame([[1,2], [1,4], [4,2]], index=[0,0.1,0.2], 
                  columns=["A", "B"])
 
 
 class TestSTLRobustness(unittest.TestCase):
-    @params(ex1, ex2)
+    @params(ex1, ex2, ex3, ex4, ex5)
     def test_lex_synth(self, phi_str, order, ranges, polarity, val):
         phi = stl.parse(phi_str)
         val2 = stl.robustness.lex_param_project(
             phi, x, order=order, ranges=ranges, polarity=polarity)
 
         phi = stl.robustness.set_params(phi, val2)
+        phi2 = stl.robustness.set_params(phi, val)
+
         stl_eval = stl.robustness.pointwise_robustness(phi)
-        self.assertAlmostEqual(stl_eval(x, 0), 0, delta=0.01)
+        stl_eval2 = stl.robustness.pointwise_robustness(phi2)
+
+        # check that the robustnesses are almost the same
+        self.assertAlmostEqual(stl_eval(x, 0), stl_eval2(x, 0), delta=0.01)
+
+        # check that the valuations are almost the same
         for var in order:
             self.assertAlmostEqual(val2[var], val[var], delta=0.01)
-