Some HITs were missing the fix for Anthony's inconsistency
Merge pull request #550 from mikeshulman/hits

2 pairs even.
Some HITs were missing the fix for Anthony's inconsistency
quotient_rect requires its motive to be an hset; close #551
Merge pull request #543 from marcbezem/master

Lemmas 3.3.2 and 3.3.3 and Exc. 3.9
Merge pull request #552 from mikeshulman/quotient

quotient_rect requires its motive to be an hset; close #551