//SINGULAR Example 2.1.34


ring A=0,(x,y,z),ds;  //local ring with max. ideal <x,y,z>
module M=[0,xy-1,xy+1],[y,xz,xz];
print(M);

print(prune(M));

ring B=0,(x,y,z),dp;              //non-local ring
module M=[0,xy-1,xy+1],[y,xz,xz]; //no units as entries
print(prune(M));

M=[0,1,xy+1],[y,xz,xz];
print(M);

print(prune(M));