fact: Definition sub' (x y : term') := ∀ $0 ∈' x`[↑] ~> $0 ∈' y`[↑].
imports: Undecidability.FOL.Util.Syntax Undecidability.FOL.Util.sig_bin Undecidability.FOL.Util.FullTarski Undecidability.FOL.Util.FullDeduction List