Morphisms from and evaluation of power series and Laurent series rings

roed314 commented 5 years ago

You can't create morphisms from power series rings to p-adic rings when you should be able to:

sage: R.<x> = ZZ[[]]
sage: A = Zp(5)
sage: R.hom([A(5)])
Traceback (most recent call last):
...
ValueError: relations do not all (canonically) map to 0 under map determined by images of generators

Moreover, you can evaluate power series on p-adic elements even when the result is not well defined:

sage: f = (x + x^4 + O(x^9))
sage: f(A(5)) # this is fine
5 + 5^4 + O(5^9)
sage: R.<x> = QQ[[]]
sage: f = (x + x^4 + O(x^9))
sage: f(A(5)) # this is not
5 + 5^4 + O(5^9)

Component: padics

Issue created by migration from https://trac.sagemath.org/ticket/28486

embray commented 4 years ago

comment:1

Ticket retargeted after milestone closed

mkoeppe commented 4 years ago

comment:2

Batch modifying tickets that will likely not be ready for 9.1, based on a review of the ticket title, branch/review status, and last modification date.

mkoeppe commented 3 years ago

comment:4

Setting new milestone based on a cursory review of ticket status, priority, and last modification date.

sagemath / sage

Morphisms from and evaluation of power series and Laurent series rings #28486