types.nat

The natural numbers. Note: all these files are ported from the standard library. If anything needs to be changed, it is probably a good idea to change it in the standard library and then port the file again (see also script/port.pl).

• basic : the natural numbers, with succ, pred, addition, and multiplication
• order : less-than, less-then-or-equal, etc.
• sub : subtraction, and distance
• div : divisibility, the mod operator, division