Merge branch 'cancel'
Merge branch 'prod'
Merge branch 'sigma'
Merge branch 'upstream'
Merge branch 'upstream'
Merge branch 'hset'
Merge branch 'upstream'
isequiv_functor_forall
types/Forall: basically done, I think.
Merge pull request #82 from mikeshulman/forall

types/Forall