fact: Definition abst_eq (pol : bool) (f1 f2: TFormula TX AF isBool) : TFormula TX AF isProp := abs_iff (REC (negb pol) f1) (REC false f2) (REC pol f1) (REC true f2) (EQ (abst_simpl f1) (abst_simpl f2)).
imports: List Refl Bool Relation_Definitions Setoid