diff -up src/sage/geometry/polyhedron/base.py.orig src/sage/geometry/polyhedron/base.py --- src/sage/geometry/polyhedron/base.py.orig 2016-08-08 13:38:11.144540312 -0400 +++ src/sage/geometry/polyhedron/base.py 2016-08-08 13:38:26.707540908 -0400 @@ -21,7 +21,6 @@ import six from sage.structure.element import Element, coerce_binop, is_Vector from sage.misc.all import cached_method, prod -from sage.misc.package import is_package_installed from sage.rings.all import QQ, ZZ from sage.rings.real_double import RDF @@ -3691,10 +3690,6 @@ class Polyhedron_base(Element): David Avis's lrs program. """ - if not is_package_installed('lrslib'): - raise NotImplementedError('You must install the optional lrslib package ' - 'for this function to work') - from sage.misc.temporary_file import tmp_filename from subprocess import Popen, PIPE in_str = self.cdd_Vrepresentation()