Type check is_isomorphic

Added a type check to .is_isomorphic to ensure that A is a quaternion algebra of the form (a,b)_K.
vbraun · Jan 20, 2024 · e3e69c2 · e3e69c2
1 parent d3173af
commit e3e69c2
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/sage/algebras/quatalg/quaternion_algebra.py b/src/sage/algebras/quatalg/quaternion_algebra.py
@@ -1091,6 +1091,9 @@ def is_isomorphic(self, A) -> bool:
             sage: A == B
             False
         """
+        if not isinstance(A, QuaternionAlgebra_ab):
+            raise TypeError("A must be a quaternion algebra of the form (a,b)_K")
+
         if self.base_ring() != QQ or A.base_ring() != QQ:
             raise NotImplementedError("isomorphism check only implemented for rational quaternion algebras")