proposition: Corollary toNat_negB n (p: BITS n) : toNat (negB p) = if toNat p == 0 then 0 else 2^n - toNat p.
proof: Proof. apply toNat_negB_or_invB. Qed.
imports: HB(structures) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq fintype tuple zmodp div) ssrextra.tuple ssrextra.nat spec spec.properties operations mathcomp(ssralg)