def fold

bend-collections-laws-crypto@1.0.0.0 · src/crypto/secp256k1/limbs.bend:133

import Base

133# lo + c hi, for x = lo + 2^256 hi: congruent to x modulo m
134def fold(+c: List<&2, Nat>, +xs: List<&2, Nat>) -> List<&2, Nat>:
135  add(take(16n, xs), conv(drop(16n, xs), c))