 LIB "ring.lib";
// The example is not shown since mapall does not work in a procedure
// (and hence not in the example procedure). Try the following commands:
// ring R=0,(x,y,z),dp;
// ideal j=x,y,z;
// matrix M[2][3]=1,2,3,x,y,z;
// map phi=R,x2,y2,z2;
// ring S=0,(a,b,c),ds;
// ideal i=c,a,b;
// mapall(R,i); //map from R to S: x>c, y>a, z>b
// names(S);
// j; print(M); phi; //phi maps R to S: x>c2, y>a2, z>b2
// ideal i1=a2,a+b,1;
// mapall(R,i1,""); //map from R to S: x>a2, y>a+b, z>1
// names(S);
// j_; print(M_); phi_;
// changevar("T","x()",R); //change vars in R and call result T
// mapall(R,maxideal(1)); //identity map from R to T
// names(T);
// j; print(M); phi;
// kill R,S,T;
