Hey John,
I'm not aware of any documentation, though there probably is some somewhere. What I can point you to is the code dealing with numbers: https://github.com/wmde/Number
Cheers
-- Jeroen De Dauw | www.EntropyWins.wtf https://EntropyWins.wtf | www.Professional.Wiki https://Professional.Wiki Entrepreneur | Software Crafter | Speaker | Open Souce and Wikimedia contributor ~=[,,_,,]:3