non/spire — pull request #37 by tixxit (2012-11-07 04:43:41+00:00)
Title: Add type class instances for UInt & ULong.

This adds a new type class, Rig, to model arithmetic without negation
(ie. no -x or x - y). It then adds instances of Rigs for all rings as
well as UInt and ULong. UInt and ULong also get new Eq and Order
instances.