Bug #1237
ker: for PolyAlgHom from QQ[x,y,z] to QQ(t)
Start date:
15 Jan 2019
Due date:
% Done:
0%
Estimated time:
Description
Should we make ker
work also for cases like the following?
>>> QQt ::= QQ[t]; >>> KQQt := NewFractionField(QQt); >>> t := indet(QQt,1); >>> embed := CanonicalHom(QQt,KQQt); >>> t := embed(t) >>> QQxy ::= QQ[x,y]; >>> phi := PolyAlgebraHom(QQxy,KQQt, [ 3*t/(t^3+1), 3*t^2/(t^3+1) ]); >>> ker(phi); --> ERROR: RINGHOM must be between poly rings or their quotients: --> [CoCoALib] ker --> ker(phi); --> ^^^^^^^^
History
#1 Updated by John Abbott about 3 years ago
- Category set to enhancing/improving
- Target version set to CoCoA-5.4.2