11 Sep
2010
11 Sep
'10
12:05 p.m.
In a bicategory, composition of 1-cells is associative up to isomorphism. Because it would be evil to insist that h o (g o f) is equal to (h o g) o f. However the source and target objects of those compositions must be equal. Isn't it evil? Why not weaken this requirement by saying that the sources (respectively, targets) of h o (g o f) and (h o g) o f must only be isomorphic? [For admin and other information see: http://www.mta.ca/~cat-dist/ ]