14 Jan
1995
14 Jan
'95
8:26 p.m.
I haven't checked the precise claim, but I think that what Peter claims is in my paper in JPAA in 1992 called Algebraically Compact Functors. The paper was, if I recall correctly, transmitted by guess who. Actually, Peter asked me in 1990 when I was leave at Penn if this were true. The paper is also available for ftp (don't tell North-Holland). I haven't studied Peter's argument, so I don't know how much it differs from mine. Actually, I haven't look at mine in several years either. A similar category, with a similar result is that of sets are injective partial functions. Interestingly, if you want to know on what category it is natural to define l^2 as a functor, it is sets and partial injections. Michael