GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
4 original generators of the toric ring 3 Hilbert basis elements of degree 1 2 extreme rays 2 support hyperplanes embedding dimension = 2 rank = 2 (maximal) external index = 2 internal index = 1 grading: 1 1 with denominator = 2 degrees of extreme rays: 1: 2 *********************************************************************** 4 original generators: 0 2 4 0 1 1 3 1 3 Hilbert basis elements of degree 1: 0 2 1 1 2 0 2 extreme rays: 0 2 2 0 2 support hyperplanes: 0 1 1 0 1 congruences: 1 1 2 2 basis elements of lattice: 1 1 0 2