fact: Definition def_pred (P : V -> Prop) := exists phi rho, forall d, P d <-> (d.:rho) ⊨ phi.
imports: Undecidability.FOL(Syntax.Facts Semantics.Tarski.FullFacts ZF) Undecidability.FOL.Sets(ZF binZF) Undecidability.FOL.Sets.Models(Aczel Aczel_CE Aczel_TD) Coq(Lia)