OrdC package:base

A case statement on Ordering. OrdCond c l e g is l when c ~ LT, e when c ~ EQ, and g when c ~ GT.
Add unsigned integers reporting overflow. The first element of the pair is the result. The second element is the carry flag, which is nonzero on overflow. See also plusWord2#.
Subtract unsigned integers reporting overflow. The first element of the pair is the result. The second element is the carry flag, which is nonzero on overflow.