fact: Definition upd h x d := nosimpl (if h is Def hs ns then if decP (@idP (x != null)) is left pf then Def (@upd_nullP _ _ d pf ns) else Undef else Undef).
imports: mathcomp(ssreflect ssrfun ssrnat div ssrbool seq) LemmaOverloading(prelude finmap ordtype) mathcomp(path eqtype) Eqdep