How to set the ring for szy computation in homalg in gap systemZZ := HomalgRing(); H := HomalgMatrix("[1,x^2+y, x*y-y*z, 0, 0 \ 0, x*z-y, z-x, 0, 0 \ 0, 0, 0, x^2+y, x*y-y*z \ 1, 0, 0, x*z-y, z-x]", 4, 5, ZZ);Regards,Martin