((∀x)A(x)→∃xB(x))∨A(x)⇔((∀x)A(x)→∃xB(x))∨∃yA(y)⇔(¬(∀x)A(x)∨∃xB(x))∨∃yA(y)⇔(∃x¬A(x)∨∃xB(x))∨∃yA(y)⇔∃x(¬A(x)∨B(x))∨∃yA(y)⇔∃x(¬A(x)∨B(x)∨∃yA(y))⇔∃x∃y(¬A(x)∨B(x)∨A(y))
