Singular

LIB "gradedModules.lib";
ring r=32003,(x,y,z),dp;
module D=grobj(module([y,0,z],[x2+y2,z,0]),intvec(0,1,0));
grview(D);
==> Graded homomorphism: r + r(-1) + r <- r(-1) + r(-2), given by a matrix, w\
   ith degrees: 
==>      ..1 ..2 ....
==>      --- --- +...
==>   0 :  1   2 |..1
==>   1 :  -   1 |..2
==>   0 :  1   - |..3
==>      === ===     
==>        1   2     
module S=grobj(module([x,0,y],[xy,zy+x2,0]),intvec(0,0,0));
grview(S);
==> Graded homomorphism: r^3 <- r(-1) + r(-2), given by a matrix, with degree\
   s: 
==>      ..1 ..2 ....
==>      --- --- +...
==>   0 :  1   2 |..1
==>   0 :  -   2 |..2
==>   0 :  1   - |..3
==>      === ===     
==>        1   2     
def H=grrndmap(D,S);
grview(H);
==> Graded homomorphism: r(-1) + r(-2) <- r(-1) + r(-2), given by a square ma\
   trix, with degrees: 
==>      ..1 ..2 ....
==>      --- --- +...
==>   1 :  0   1 |..1
==>   2 :  -   0 |..2
==>      === ===     
==>        1   2