Make extracting information about a PARI group less painful

[slel]

Requested by John Cremona on sage-devel:

• https://groups.google.com/d/topic/sage-devel/xEXdPgg2kfM/discussion

see issue 51 in cypari2.

Upstream: Reported upstream. Developers acknowledge bug.

CC: @JohnCremona @slel

Component: packages: standard

Keywords: PARI group, Galois group

Issue created by migration from https://trac.sagemath.org/ticket/24469

[videlec]

comment:1

I think this should be addressed by upstream cypari2. The point is that GP provides shortcut to access some members

$ gp
? K = bnfinit(x^3 - 2);
? bnf = bnfinit(x^3 - 2);
? bnf.nf     /* = bnf[7] */
%3 = [x^3 - 2, [1, 1], -108, 1, ...]
? bnf.clgp   /* = bnf[8][1] */
%4 = [1, [], []]

(these do not exist in the PARI library). The same shortcuts should be available on the Gen type

sage: K = pari.bnfinit('x^3 - 2')
sage: K.nf
Traceback (most recent call last):
...
AttributeError: 'cypari2.gen.Gen' object has no attribute 'nf'

[videlec]

Upstream: Reported upstream. Developers acknowledge bug.

[JohnCremona]

comment:4

The bnf example is not quite relevant here, is it? The components of the Galois group are not currently accessible by such shortcuts (as far as I know).

[slel]

comment:5

Change milestone to sage-wishlist for a few tickets whose previous milestone is closed.