CoCoA » CoCoALib

Making a homomorphism is often tedious. In CoCoA-5 we need to write (the best we can do):

 QQy ::= QQ[y];
 R := NewQuotientRing(QQy, ideal(RingElem(QQy,"y^2-5")));
 phi := PolyAlgebraHom(QQt(1), R, [RingElem(R,"(1+y)/2")]);

Consider the syntax:

 phi := PolyAlgebraHom(QQt(1), R, "(1+y)/2");

where the string is automatically read in the codomain.
(similar for NewQuotientRing)

2019-10 Done. Example:

phi := PolyAlgebraHom(R, S, "a,1,0");