From db79f1e37c35761078fb3e4cbce444f4670461f7 Mon Sep 17 00:00:00 2001
From: Jonathan Kliem <jonathan.kliem@fu-berlin.de>
Date: Thu, 20 Feb 2020 16:48:50 +0100
Subject: [PATCH] little improvement

---
 src/sage/geometry/polyhedron/combinatorial_polyhedron/base.pyx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/sage/geometry/polyhedron/combinatorial_polyhedron/base.pyx b/src/sage/geometry/polyhedron/combinatorial_polyhedron/base.pyx
index f5f97fa3497..dfee0088c9f 100644
--- a/src/sage/geometry/polyhedron/combinatorial_polyhedron/base.pyx
+++ b/src/sage/geometry/polyhedron/combinatorial_polyhedron/base.pyx
@@ -1568,7 +1568,7 @@ cdef class CombinatorialPolyhedron(SageObject):
                         vertices[one] = 0
                         vertices[two] = 0
 
-        return all(x == 0 for x in vertices)
+        return not any(vertices)
 
     def is_pyramid(self, certificate=False):
         r"""