Composition laws via stacks

Composition law paper todo:

a) Go over composition law proofs

b) Think about applications to composition laws

  do comp laws hold over arbitrary rings?

  try to use the "kernel thing" to generate new composition laws. (Need non-special groups. The usual setup uses pre-homogenous spaces. Maybe find some 'near misses' -- i.e., setups that people don't study because they don't give PHV's

  I don't really understand yet how people use composition laws to prove other cool theorems.

  Melanie and Dan's paper, references to Melanie's thesis, etc