fact: Fixpoint incB {n} : BITS n -> BITS n := if n is n.+1 then fun p => let (p,b) := eta_expand (splitlsb p) in if b then joinlsb (incB p, false) else joinlsb (p, true) else fun _ => nilB.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq tuple) spec