Hello, I am having particular trouble with the below problem. We are using http://studygig.com/uploads/materials/math1090_mathematical_logi.pdf [Broken] and we must prove this statement using Hilbert style or Equational style proof (first-order logic), but any proof of any type would point me in the right direction. (∀x)(A→B) ≡ ((∃x)A) → B So far I have tried to use Ping-Pong Theorem to prove that 1. (∀x)(A→B) → (((∃x)A) → B) and 2. (((∃x)A) → B) → (∀x)(A→B) but I can't prove either 1. or 2. If anyone could provide insight, I would appreciate it.