Singular

D.4.2.10 mapIsFinite

Usage:

mapIsFinite(phi,R[,J]); R the preimage ring of the map phi: R ---> basering
J an ideal in the basering, J = 0 if not given

Return:

1 if R ---> basering/J is finite and 0 else

Note:

R may be a quotient ring (this will be ignored since a map R/I-->S/J is finite if and only if the induced map R-->S/J is finite).

LIB "algebra.lib";
ring r = 0,(a,b,c),dp;
ring s = 0,(x,y,z),dp;
ideal i= xy;
map phi= r,(xy)^3+x2+z,y2-1,z3;
mapIsFinite(phi,r,i);
==> 1