GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
Read( "ReducedBasisOfModule.g" ); II_E := GrothendieckSpectralSequence( RightDualizingFunctor( Qxyz ), LeftDualizingFunctor( Qxyz ), W ); filt := FiltrationBySpectralSequence( II_E ); m := IsomorphismOfFiltration( filt );