//SINGULAR ExampleA.8.4



ring R = 0,(x,y,z),dp;   //global affine ring
ideal I = xz,yz;
dim(std(I));

ring r = 0,(x,y,z),ds;   //localization of R at (0,0,0)
ideal I = imap(R,I);
dim(std(I));

map phi1 = r,x-1,y,z;    //maps the point (1,0,0) to (0,0,0)
ideal I1 = phi1(I); 
dim(std(I1));

map phi2 = r,x,y,z-1;    //maps the point (0,0,1) to (0,0,0)
ideal I2 = phi2(I); 
dim(std(I2));