> Now we are getting somewhere, maybe. I'm thinking of the
> natural (to me!) right action and you're thinking
> of the left action got by inverting the permutation and acting
> in the natural way :-).
>
> I guess I just don't think permutation (which are functions) should
> act on the left. It's repulsive to me. I guess there's just
> not much more to say than that.
>
> -- William
GAP's permutation multiplication does not correspond to how we would
normally read a composition of functions. For the Permutation class I
wrote, multiplication is determined by PermutationOptions(). The
default (for now) matches up with GAP:
sage: PermutationOptions()
{'display': 'list', 'mult': 'l2r'}
sage: a = Permutation('(1,2,3)(4,5)'); a
(1,2,3)(4,5)
sage: b = Permutation('(1,2,3,4,5)'); b
(1,2,3,4,5)
sage: a*b
(1,3,2,4)
sage: b*a
(1,3,5,2)
But, you can switch it to do the more natural (for me) thing:
sage: PermutationOptions(mult='r2l')
sage: a*b
(1,3,5,2)
sage: b*a
(1,3,2,4)
--Mike
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