Date: Nov 15, 2012 4:28 AM Author: William Elliot Subject: Ultranet What's an example of an universal or ultranet?
Wikipedia claims that if n:D -> X is an ultranet into X and
f:X -> Y, then the composition f.n:D -> Y is an ultranet into Y.
I dispute the claim but knowing of no examples
of ultranets, I'm bankrupt for a counter example.