fact: CoInductive defUn_spec h1 h2 : bool -> Type := | def_false1 of ~~ def h1 : defUn_spec h1 h2 false | def_false2 of ~~ def h2 : defUn_spec h1 h2 false | def_false3 x of x \in dom h1 & x \in dom h2 : defUn_spec h1 h2 false | def_true of def h1 & def h2 & (forall x, x \in dom h1 -> x \notin dom h2) : defUn_spec h1 h2 true.
imports: mathcomp(ssreflect ssrfun ssrnat div ssrbool seq) LemmaOverloading(prelude finmap ordtype) mathcomp(path eqtype) Eqdep