-- -*- M2-comint -*- {* hash: -1977422905 *}

i1 : P = convexHull matrix {{1,-1,0,0},{0,0,1,-1}}

o1 = {ambient dimension => 2           }
      dimension of lineality space => 0
      dimension of polyhedron => 2
      number of facets => 4
      number of rays => 0
      number of vertices => 4

o1 : Polyhedron

i2 : dim P

o2 = 2

i3 :