机构:
Univ Paris Est Creteil, IUT Senart Fontainebleau, EA 4219, LACL, Creteil, FranceUniv Paris Est Creteil, IUT Senart Fontainebleau, EA 4219, LACL, Creteil, France
Cegielski, Patrick
[1
]
Grigorieff, Serge
论文数: 0引用数: 0
h-index: 0
机构:
CNRS, UMR 8243, IRIF, Paris, France
Univ Paris 07, Paris, FranceUniv Paris Est Creteil, IUT Senart Fontainebleau, EA 4219, LACL, Creteil, France
Grigorieff, Serge
[2
,3
]
Guessarian, Irene
论文数: 0引用数: 0
h-index: 0
机构:
CNRS, UMR 8243, IRIF, Paris, France
Univ Paris 07, Paris, France
UPMC Univ Paris 6, Paris, FranceUniv Paris Est Creteil, IUT Senart Fontainebleau, EA 4219, LACL, Creteil, France
Guessarian, Irene
[2
,3
,4
]
机构:
[1] Univ Paris Est Creteil, IUT Senart Fontainebleau, EA 4219, LACL, Creteil, France
A function on an algebra is congruence preserving if for any congruence, it maps congruent elements to congruent elements. We show that on a free monoid generated by at least three letters, a function from the free monoid into itself is congruence preserving if and only if it is of the form for some finite sequence of words . We generalize this result to functions of arbitrary arity. This shows that a free monoid with at least three generators is a (noncommutative) affine complete algebra. As far as we know, it is the first (nontrivial) case of a noncommutative affine complete algebra.