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About: About this document is_cenSubbimodule
Procedure from library nchomolog.lib (see nchomolog_lib).

is_cenSubbimodule(M); M module

1, if a subbimodule, generated by the columns of M is centralizing in the sense of Artin and 0 otherwise

LIB "nchomolog.lib";
def A = makeUsl2(); setring A;
poly p = 4*e*f + h^2-2*h; // generator of the center
matrix M[2][2] = p, p^2-7,0,p*(p+1);
is_cenSubbimodule(M); // M is centralizing subbimodule
==> 1
matrix N[2][2] = p, e*f,h,p*(p+1);
is_cenSubbimodule(N); // N is not centralizing subbimodule
==> 0