### Cohomology and Computation (Week 25)

#### Posted by John Baez

In this week’s seminar on Cohomology and Computation, we put the pieces together and saw how to build simplicial objects from adjoint functors. Next time we’ll see what they’re actually like, in an example:

- Week 25 (May 24) - The bar construction, continued. The zig-zag identities for the unit and counit of an adjunction. Monads and comonads from adjunctions. Simplicial objects from adjunctions.

Last week’s notes are here; next week’s notes are here.

Posted at June 6, 2007 5:09 PM UTC
## Re: Cohomology and Computation (Week 25)

Might $\Delta$ have a Leinster-Euler cardinality, using trickery if necessary? How many order preserving maps from [$m$] to [$n$] are there?