The statement A→B→A is equivalent to:
A→A∧B
A→A→B
A→A∨B
A→A↔B
Given statement: A⟶(B→A) ≃~A∨(B→A) ≃~A∨(~B∨A)∣ ≃(~A∨A)∨B ≃t∨B≃t (3) ⇒A→(A∨B)≃~A∨(A∨B) ≃(~A∨A)∨B ≃≈t∨B ≃t