fact: Definition PA7 (f : Formula) (v : nat) : Formula := let f_0 := substF f v Zero%nt in let f_Sv := substF f v (Succ v#v)%nt in close _ (f_0 -> (allH v, f -> f_Sv) -> allH v, f)%nt.
imports: Coq(Arith Lia Ensembles Decidable) hydras.Ackermann(folProp subAll folLogic3) hydras.Ackermann(NewNotations)