It turns out that methods are not of function type.

Excuse me while I roll my eyes.
Apparently the producer for bools was broken. Oops.
Allow removal of pairs from lists when simplifying.
while we're at it add a test for simultaneously simplifying pairs of ints here too
This is a very crude sketch of how stateful testing might work with hypothesis.

It's not even close to finished, but it at least demonstrates the basic concept
of how it might work.