def off.len_zeros
import bend-osdev-bytes@0.1.1.0/PROOF.bend as PROOFimport Base
import bend-osdev-bytes@0.1.1.0/bytes.bend as B
927def off.len_zeros(+n: Nat) -> {List.length(&2, B.OctByte, B.w8s.zeros(n)) == n : Nat}:
928 match n:
929 case 0n:
930 {==}
931 case 1n+p:
932 Equal.cong(Nat, Nat, k => 1n+k, List.length(&2, B.OctByte, B.w8s.zeros(p)), p, off.len_zeros(p))