Theorem subj_from_disj

Theorem. subj_from_disj
(¬A ∨ B) → (A → B)
Proof
01. 1 ⊢ ¬A ∨ B, hypo.
02. 2 ⊢ A, hypo.
03. 3 ⊢ ¬A, hypo.
04. 2, 3 ⊢ ⊥, neg_elim 3 2.
05. 2, 3 ⊢ B, efq 4.
06. 6 ⊢ B, hypo.
07. 1, 2 ⊢ B, disj_elim 1 5 6.
08. 1 ⊢ A → B, subj_intro 7.
subj_from_disj. ⊢ (¬A ∨ B) → (A → B), subj_intro 8.

Dependencies
The given proof depends on one axiom:
efq.