Re: PARI 2.6 syntax 2: [f(x)|x<-a,b(x)]

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Fri, Mar 08, 2013 at 10:03:48AM +0000, Phil Carmody wrote:
> --- On Fri, 3/8/13, Andreas Enge <andreas.enge@inria.fr> wrote:
> > On Fri, Mar 08, 2013 at 08:01:25AM +0100, Pascal Molin wrote:
> > > Well @ is still available, no ? The email analogy is OK : "in the following
> > > domain"
> > 
> > Magma uses the keyword "in", which is quite reasonable.
> 
> If we're brainstorming, \in springs to mind.

\ is already an infix operator, and a \in b would read as a\inb, i.e. a division.

> If we're on the topic of that operator, is there any reason it doesn't act as a predicate?
> 
> ? excludes=[2,3,5]
> %1 = [2, 3, 5]
> ? [x^2|x <- [1..100],!x <- excludes]
>   ***   at top-level: [x^2|x<-[1..100],!x<-excludes]

The intent is for <- to be a generator not a predicate.

Cheers,
Bill.