ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Sun, 07 Feb 2021 17:41:51 +0100possible bug: kernel of ring homomorphismhttps://ask.sagemath.org/question/55618/possible-bug-kernel-of-ring-homomorphism/ The kernel of a ring homomorphism to a quotient ring gives unexpected results:
A.<t> = QQ[]
B.<x,y> = QQ[]
H = B.quotient(B.ideal([B.1]))
f = A.hom([H.0], H)
f
f.kernel()
outputs:
Ring morphism:
From: Univariate Polynomial Ring in t over Rational Field
To: Quotient of Multivariate Polynomial Ring in x, y over Rational Field by the ideal (y)
Defn: t |--> xbar
Principal ideal (t) of Univariate Polynomial Ring in t over Rational Field
whereas the kernel of f:A[t]->B[x,y]->B[x,y]/(y), for f(t)=x should be (0).
Why?makosSun, 07 Feb 2021 17:41:51 +0100https://ask.sagemath.org/question/55618/