Theorem lsubj_elim

Theorem. lsubj_elim
(A ↔ B) → A → B
Proof
01. 1 ⊢ A ↔ B, hypo.
02. 1 ⊢ A → B, bij_eliml 1.
lsubj_elim. ⊢ (A ↔ B) → A → B, subj_intro 2.