Add test for 'Segment.op_Inequality' method

tests/segment_tests/test_op_Inequality.py

@@ -0,0 +1,20 @@
+from hypothesis import given
+
+from tests.binding import Segment
+from tests.utils import equivalence
+from . import strategies
+
+
+@given(strategies.segments)
+def test_irreflexivity(segment: Segment) -> None:
+    assert not segment != segment
+
+
+@given(strategies.segments, strategies.segments)
+def test_symmetry(first: Segment, second: Segment) -> None:
+    assert equivalence(first != second, second != first)
+
+
+@given(strategies.segments, strategies.segments)
+def test_equivalents(first: Segment, second: Segment) -> None:
+    assert equivalence(first != second, not first == second)