Fixed point of word morphism is broken on some tuple input

[seblabbe]

From sage-combinat-devel group :

2010/3/23 Vincent Delecroix
> Hi,
>
> I tried the following and get an unexpected error
>
> {{{
> sage: s = WordMorphism({'a1': ['a1','a2'], 'a2':['a1']})
> sage: s.fixed_point('a1')
> Traceback
> ...
> KeyError: 'a'
> }}}
>
> and it does the same for tuples
>
> {{{
> sage: s = WordMorphism({('a', 1) : [('a', 1), ('a', 2)], ('a', 2) : [('a', 1)]})
> sage: s.fixed_point(('a', 1))
> Traceback
> ...
> KeyError: 'a'
> }}}
>
> Is it a bug or not the right way to do ?
>
> (On this example it looks strange but I really need product alphabet)
>
> Cheers,
> Vincent

CC: @videlec

Component: combinatorics

Author: Sébastien Labbé

Reviewer: Vincent Delecroix

Merged: sage-4.4.alpha0

Issue created by migration from https://trac.sagemath.org/ticket/8595

[seblabbe]

Attachment: trac_8595_fixed_point-sl.patch.gz

[videlec]

comment:3

The bug seems to be resolved by the patch! Great.

[videlec]

Reviewer: vdelecroix

[jhpalmieri]

Changed reviewer from vdelecroix to Vincent Delecroix

[jhpalmieri]

Author: Sébastien Labbé

[jhpalmieri]

comment:4

Merged "trac_8595_fixed_point-sl.patch" in 4.4.alpha0.

[jhpalmieri]

Merged: sage-4.4.alpha0