GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
LoadPackage( "MatricesForHomalg" ); ZZ := HomalgRingOfIntegers( ); m := HomalgMatrix( "[ \ 2, 0, 0, \ 0, 12, 0 \ ]", 2, 3, ZZ ); Assert( 0, Minors( -1, m ) = [ 1 ] ); Assert( 0, Minors( 0, m ) = [ 1 ] ); Assert( 0, Minors( 1, m ) = [ 2, 12 ] ); Assert( 0, Minors( 2, m ) = [ 24 ] ); Assert( 0, Minors( 3, m ) = [ 0 ] ); Assert( 0, Minors( 4, m ) = [ 0 ] );