Definition codeFormula := codeFormula LNT codeLNTFunction codeLNTRelation.Definition T' : fol.System LNN :=
  Union _ NN
    (fun x : fol.Formula LNN => mem _ T (LNN2LNT_formula x)).

Lemma freeVarRepT' : forall v : nat, In v (freeVarFormula LNN (LNT2LNN_formula repT)) -> v = v0.