proposition: Theorem le_induction {n p} (Hp: p <= n) (P: forall p (Hp: p <= n), Type) (H_base: P n (♢ n)) (H_step: forall p (Hp: p.+1 <= n) (H: P p.+1 Hp), P p (↓ Hp)): P p Hp.
proof: Proof. induction (leYind_construct Hp); now auto. Defined.
imports: Bonak(Notation) Bonak(LeInductive)