induction on the proof structure. ⊓⊔ inria-00395934, version 2 - 23 Jun 2009 Proposition 12. All inference rules of LBi but −⇒ and −∀ are invertible, and the proofs of their premises is smaller or equal for the proof skeleton ordering. Nonetheless, when t (0)

by By
Venue:Lemma 13. If Γ, P, P ⊢ ∆ then Γ, P ⊢ ∆ with