Section DEDUCTION_THEOREM.
End DEDUCTION_THEOREM.
#[local] Existing Instance V.vec_isSetoid.

Lemma for_Imp_E (Gamma : ensemble (frm L)) (p : frm L) (q : frm L)
(PROVE1 : Gamma \proves Imp_frm p q)
(PROVE2 : Gamma \proves p)
: Gamma \proves q.