b B x B b x b c d x B c D x D d x d D x a P x a b b x B P x P b x b c d x P c Q x Q D x d Q x Q e x d d e x 2.2 b c d x D x D d x D x a P x a b b x a P x b x b B x B b x a P x b b x B P x b x b c d x Q x b c d x B c D x b B x b x Q D x Q x true a P x a b b x true Failed! NaTT certifiable-1.6