GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
6 extreme rays 5 support hyperplanes embedding dimension = 4 rank = 4 (maximal) external index = 1 internal index = 1 original monoid is not integrally closed witness for not being integrally closed: 2 2 0 1 ideal is primary to the ideal generated by the indeterminates *********************************************************************** 6 extreme rays: 0 0 1 0 0 0 1 1 0 1 0 0 0 5 0 1 1 0 0 0 3 0 0 1 5 support hyperplanes: 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 5 3 15 -15