GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
Read( "Markus_Lokalisierung.g" ); II_E := GrothendieckSpectralSequence( RightDualizingFunctor( A2 ), LeftDualizingFunctor( A2 ), M ); ii_E := GrothendieckSpectralSequence( RightDualizingFunctor( A2 ), LeftDualizingFunctor( A2 ), N ); ByASmallerPresentation( II_E ); ByASmallerPresentation( ii_E ); filt := FiltrationBySpectralSequence( II_E ); filtN := FiltrationBySpectralSequence( ii_E ); m := IsomorphismOfFiltration( filt ); n := IsomorphismOfFiltration( filtN );