sign ==== [![Build Status](https://secure.travis-ci.org/msakai/sign.png?branch=master)](http://travis-ci.org/msakai/sign) [![Hackage](https://budueba.com/hackage/sign)](https://hackage.haskell.org/package/sign) [![Coverage Status](https://coveralls.io/repos/msakai/sign/badge.svg)](https://coveralls.io/r/msakai/sign) Arithmetic over signs (i.e. {-,0,+}) and sets of signs