GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
1 extreme rays 1 support hyperplanes embedding dimension = 2 rank = 2 (maximal) external index = 1 internal index = 1 dimension of maximal subspace = 1 grading: 1 1 degrees of extreme rays: 1: 1 *********************************************************************** 1 extreme rays: 1 0 1 basis elements of maximal subspace: 1 -1 1 support hyperplanes: 1 1