LIB "ring.lib";
ring rng = 0,x,dp;
isQuotientRing(rng); //no
==> 0
// if a certain method does not support quotient rings,
// then a parameter test could be performed:
ASSUME( 0, 0==isQuotientRing(basering));
qring q= ideal(x);  // constructs rng/ideal(x)
isQuotientRing(q);  // yes
==> 1