Trac 18246: fix __hash__ in homology

src/sage/homology/cubical_complex.py

@@ -823,6 +823,21 @@ def __cmp__(self,other):
         else:
             return -1
 
+    def __hash__(self):
+        r"""
+        TESTS::
+
+            sage: I1 = cubical_complexes.Cube(1)
+            sage: I2 = cubical_complexes.Cube(1)
+            sage: hash(I1)
+            2025268965           # 32-bit
+            6535457225869567717  # 64-bit
+            sage: hash(I1.product(I1))
+            4177112485           # 32-bit
+            -1640877824464540251 # 64-bit
+        """
+        return hash(frozenset(self._facets))
+
     def is_subcomplex(self, other):
         r"""
         Return True if ``self`` is a subcomplex of ``other``.

src/sage/homology/delta_complex.py

@@ -474,6 +474,19 @@ def subcomplex(self, data):
         sub._is_subcomplex_of = {self: new_data}
         return sub
 
+    def __hash__(self):
+        r"""
+        TESTS::
+
+            sage: hash(delta_complexes.Sphere(2))
+            3505125070           # 32-bit
+            -5090854238868998450 # 64-bit
+            sage: hash(delta_complexes.Sphere(4))
+            376965290           # 32-bit
+            8539734868592429226 # 64-bit
+        """
+        return hash(frozenset(self._cells_dict.items()))
+
     def __cmp__(self,right):
         r"""
         Two `\Delta`-complexes are equal, according to this, if they have