From be6aedc732144e17911e00505e699ed7c48d5442 Mon Sep 17 00:00:00 2001
From: Lorenz Panny <lorenz@yx7.cc>
Date: Tue, 18 Oct 2022 03:39:42 +0800
Subject: [PATCH] fix doctest failures

---
 src/sage/schemes/elliptic_curves/hom_scalar.py   |  6 +-----
 src/sage/schemes/elliptic_curves/hom_velusqrt.py | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/sage/schemes/elliptic_curves/hom_scalar.py b/src/sage/schemes/elliptic_curves/hom_scalar.py
index f59b76288cd..8cdbef44f9f 100644
--- a/src/sage/schemes/elliptic_curves/hom_scalar.py
+++ b/src/sage/schemes/elliptic_curves/hom_scalar.py
@@ -307,12 +307,8 @@ def _richcmp_(self, other, op):
         TESTS::
 
             sage: from sage.schemes.elliptic_curves.weierstrass_morphism import negation_morphism
-            sage: from sage.schemes.elliptic_curves.hom_composite import EllipticCurveHom_composite
-            doctest:warning ...
             sage: neg = negation_morphism(E)
-            sage: neg_psi = EllipticCurveHom_composite.from_factors([psi,neg])
-            sage: psi_neg = EllipticCurveHom_composite.from_factors([neg,psi])
-            sage: phi == neg_psi == psi_neg == -psi
+            sage: phi == neg*psi == psi*neg == -psi
             True
         """
         if isinstance(other, EllipticCurveHom_scalar):
diff --git a/src/sage/schemes/elliptic_curves/hom_velusqrt.py b/src/sage/schemes/elliptic_curves/hom_velusqrt.py
index 144b5400970..21e0b6c0187 100644
--- a/src/sage/schemes/elliptic_curves/hom_velusqrt.py
+++ b/src/sage/schemes/elliptic_curves/hom_velusqrt.py
@@ -1365,6 +1365,22 @@ def scaling_factor(self):
         """
         return self._pre_iso.scaling_factor() * self._post_iso.scaling_factor()
 
+    def is_separable(self):
+        r"""
+        Determine whether or not this isogeny is separable.
+
+        Since :class:`EllipticCurveHom_velusqrt` only implements
+        separable isogenies, this method always returns ``True``.
+
+        EXAMPLES::
+
+            sage: E = EllipticCurve(GF(17), [0,0,0,3,0])
+            sage: phi = E.isogeny(E((1,2)), algorithm='velusqrt')
+            sage: phi.is_separable()
+            True
+        """
+        return True
+
 
 def _random_example_for_testing():
     r"""