fact: Definition Formula_depth_rec (P : Formula -> Set) (rec : forall a : Formula, (forall b : Formula, lt_depth b a -> P b) -> P a) (a : Formula) : P a := Formula_depth_rec_rec P rec (depth a) a (le_n (depth a)).
imports: Coq(Lists.List Ensembles Peano_dec Eqdep_dec Arith Compare_dec Utf8) hydras(Ackermann.misc Compat815 )