GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
LoadPackage( "RingsForHomalg" ); LoadPackage( "Modules" ); Qxy := HomalgFieldOfRationalsInDefaultCAS( ) * "x,y"; YI := HomalgMatrix( "[ \ y^2-x*(x-1)*(x+1), 0, 0, \ 0, x, 0, \ 0, y, 0, \ 0, 0, x, \ 0, 0, y-1 \ ]", 5, 3, Qxy ); Y := LeftPresentation( Involution( YI ) ); Yt := TorsionObject( Y ); Ann := Annihilator( Yt );