- pmul: \( (a, b) \to (r, s) \) where \( r s = a \otimes b \), i.e. \( r \) is the upper word of the result, and \( s \) is the lower word.
- pdiv.mod: \( (a, b) \to (q, r) \) where \( q \otimes b = a \oplus r \), i.e. \( q \) is the quotient and \( r \) is the remainder.
It's been a while since I last studied abstract algebra, so I might not have gotten all my terminology correct, but you get the idea.