Raise TypeError if Polyhedron.widen() is called on a non-polyhedral argument

diff --git a/linpy/polyhedra.py b/linpy/polyhedra.py
index fb2b4a7..e5e2523 100644 (file)
--- a/linpy/polyhedra.py
+++ b/linpy/polyhedra.py
@@ -178,7 +178,7 @@ class Polyhedron(Domain):
         used on large polyhedra.
         """
         if not isinstance(other, Polyhedron):
-            raise ValueError('argument must be a Polyhedron instance')
+            raise TypeError('argument must be a Polyhedron instance')
         inequalities1 = self._asinequalities()
         inequalities2 = other._asinequalities()
         inequalities = []