GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
## Bahman Engheta's Thesis: Bounds on Projective Dimension, Example 1.5 LoadPackage( "RingsForHomalg" ); R := HomalgFieldOfRationalsInDefaultCAS( ) * "a,b,c,d,e,f"; LoadPackage( "Modules" ); I := LeftSubmodule( "a*c*e, b*d*f, a*b*c*d + a*b*e*f + c*d*e*f", R ); M := FactorObject( I ); Assert( 0, ProjectiveDimension( M ) = 5 );