-- -*- M2-comint -*- {* hash: 612934 *}

i1 : F = fan {posHull matrix {{1,0},{0,1}},posHull matrix {{0,-1},{1,1}},posHull matrix {{-1,-1},{0,1}},posHull matrix {{-1,1},{0,-1}},posHull matrix {{1,1},{0,-1}}}

o1 = {ambient dimension => 2         }
      number of generating cones => 5
      number of rays => 5
      top dimension of the cones => 2

o1 : Fan

i2 : P = polytope F

o2 = {ambient dimension => 2           }
      dimension of lineality space => 0
      dimension of polyhedron => 2
      number of facets => 5
      number of rays => 0
      number of vertices => 5

o2 : Polyhedron

i3 :