Log Message:
Import spin-5.2.0 as wip/spin.

Spin is an efficient on-the-fly verification system
(a `model checker') for asynchronous concurrent systems,
such as data communication protocols, distributed operating
systems, database systems, etc.
It can be used to prove both safety and liveness properties,
including all correctness requirements expressible in linear
time temporal logic.
Spin uses a high level language to specify systems descriptions,
called PROMELA (PROcess MEta LAnguage).