Update src/sage/homology/homology_vector_space_with_basis.py

Co-authored-by: Travis Scrimshaw <[email protected]>
jhpalmieri · Sep 23, 2023 · 9df8bba · 9df8bba
1 parent 647c9bd
commit 9df8bba
Showing 1 changed file with 4 additions and 5 deletions.
diff --git a/src/sage/homology/homology_vector_space_with_basis.py b/src/sage/homology/homology_vector_space_with_basis.py
@@ -690,11 +690,10 @@ def _acted_upon_(self, a, self_on_left):
             if m <= n:
                 return self.parent().zero()
 
-            vec = []
-            for x in sorted(self.parent().dual().basis(m-n)):
-                vec.append(self.eval(a * x))
-            B = list(self.parent().basis(m-n))
-            return self.parent().linear_combination(zip(B, vec))
+            P = self.parent()
+            B = list(P.basis(m-n))
+            return P._from_dict({b.support()[0]: self.eval(a * x)
+                                 for x in sorted(self.parent().dual().basis(m-n))})
 
 
 class CohomologyRing(HomologyVectorSpaceWithBasis):