def comb_bits
import bend-collections@1.0.0.0/src/containers/bitset.bend as Bitsetimport Base
import bend-collections@1.0.0.0/src/containers/types/bitset.bend as E
478def comb_bits(+k: WordOp, s: Bitset, +ys: List<&2, Bool>) -> Bitset & Result<&2, &2, E.Error, Unit>:
479 match s:
480 case BS{+n, +d, a}:
481 comb_go(Nat.is_eq(n, bool_count(ys)), k, n, d, a, ys)