fact: Fixpoint nat_ind (P:nat->Prop)(exp1:P 0) (exp2:forall p:nat, P p -> P (S p))(n:nat){struct n} : P n := match n as x return P x with | O => exp1 | S p => exp2 p (nat_ind P exp1 exp2 p) end.
imports: ZArith List Arith Zwf Relations Inverse_Image