f a f c a f c X X f c a f d b f a f d a f d X X f c b f d a e g X e X 2.2 e g X e X f a f d a f c a f d b f c b f d a f a f c a true f a f c a false f c b f d a false f c a f d b false f a f d a false e g X e X true a 0 0 d 1 0 b 0 0 e 1 1 0 c 1 0 f 1 0 f 1 0 e 1 0 g 1 1 1 NaTT certifiable-1.6