Notation Formula := (Formula L) (only parsing).Notation Formulas := (Formulas L) (only parsing).Notation System := (System L) (only parsing).Notation Term := (Term L) (only parsing).Notation Terms := (Terms L) (only parsing).Notation var := (var L) (only parsing).Notation apply := (apply L) (only parsing).Notation equal := (equal L) (only parsing).Notation atomic := (atomic L) (only parsing).Notation impH := (impH L) (only parsing).Notation notH := (notH L) (only parsing).Notation forallH := (forallH L) (only parsing).Notation iffH := (iffH L) (only parsing).Notation SysPrf := (SysPrf L) (only parsing).Fixpoint subAllTerm (t : fol.Term L) : (nat -> fol.Term L) -> fol.Term L :=
  match t return ((nat -> fol.Term L) -> fol.Term L) with
  | fol.var x => fun m => m x
  | fol.apply f ts => fun m => fol.apply L f (subAllTerms _ ts m)
  end
 
 with subAllTerms (n : nat) (ts : fol.Terms L n) {struct ts} :
 (nat -> fol.Term L) -> fol.Terms L n :=
  match
    ts in (fol.Terms _ n) return ((nat -> fol.Term L) -> fol.Terms L n)
  with
  | Tnil => fun _ => Tnil L
  | Tcons n' t ss =>
      fun m => Tcons L n' (subAllTerm t m) (subAllTerms _ ss m)
  end.

Lemma subAllTerms_ext : forall (n : nat) (ts : fol.Terms L n) (m1 m2 : nat -> fol.Term L), (forall m : nat, In m (freeVarTerms L n ts) -> m1 m = m2 m) -> subAllTerms n ts m1 = subAllTerms n ts m2.