PART_MATCH' : (term -> term) -> thm -> term -> thm
> IMP_DISJ_THM; val it = ⊢ ∀A B. A ⇒ B ⇔ ¬A ∨ B: thm > PART_MATCH (rand o lhs) IMP_DISJ_THM “p /\ A”; val it = ⊢ A ⇒ p ∧ A ⇔ ¬A ∨ p ∧ A: thm > PART_MATCH' (rand o lhs) IMP_DISJ_THM “p /\ A”; val it = ⊢ ∀A'. A' ⇒ p ∧ A ⇔ ¬A' ∨ p ∧ A: thm