-- -*- M2-comint -*- {* hash: 1496026041 *}

i1 : C1 = posHull matrix {{1,0},{0,1}};

i2 : C2 = posHull matrix {{1,-1},{0,-2}};

i3 : C3 = posHull matrix {{0,-2},{1,-1}};

i4 : C4 = posHull matrix {{-1,-2},{-2,-1}};

i5 : F = fan{C1,C2,C3,C4}

o5 = {ambient dimension => 2         }
      number of generating cones => 4
      number of rays => 4
      top dimension of the cones => 2

o5 : Fan

i6 : isPolytopal F

o6 = true

i7 :