Re: PARI/GP vecsort/versearch and Mod()

Bill Allombert <[email protected]> Sat, 15 Nov 2025 17:01:54 +0100

Newsgroups	gmane.comp.mathematics.pari.user
Message-ID	<aRij8sBX_mDtmQMg@seventeen>

On Sat, Nov 15, 2025 at 03:48:05PM +0100, [email protected] wrote:
> I wanted to check four 2x2 matrixes with entries in ℤ/2ℤ to be closed under
> matrix addition and multiplication.
> 
> Because of missing order relation for Mod() using vecsort/vecsearch directly
> was no option. 

You have three options:
- Use Set and setsearch
- use Map and mapisdefined
- use vecsort/vecsearch but apply lift to the vectors/ elements to remove the Mod.

Cheers,
Bill.