AB¬A¬BA∧B¬(A∧B)¬A∨¬B¬(A∧B)⇔¬A∧¬BXY¬X¬YX∧Y¬(X∧Y)¬X∨¬Y¬(X∧Y)⇔¬X∨¬YCD¬C¬DC∧D¬(C∧D)¬C∨¬D¬(C∧D)⇔¬C∨¬DEF¬E¬FE∧F¬(E∧F)¬E∨¬F¬(E∧F)⇔¬E∨¬F
