Le samedi 26 Novembre 2005 18:42, vous avez écrit :

In answer to Carl Futia

Charles Ehresmann has called such "gadgets" quasi-categories in "Introduction to the theory of structured categories" (Kansas 1966) reprinted in "Charles Ehresmann: Oeuvres completes et commentees" Part III-2.

Sincerely Andree C. Ehresmann

Dear All, One told me very recently that Joyal is writting a book about "quasi-categories". But with a different meaning. A quasi-category is a simplicial set satisfying a condition a little bit weaker than the Kan condition. Morally speaking, two composable arrows have several possible compositions, up to homotopy. I dont know whether Joyal reads this mailing-list ? pg.