fact: Definition bench := Ands (Iff be1_cpos be2_cpos :: Iff be1_cst2 be2_cst2 :: Iff be1_sqb be2_sqb :: Iff be1_cneg be2_cneg :: Iff be1_cas be2_cas :: Iff be1_csh be2_csh :: Iff be1_cas1 be2_cas1 :: nil).