f a f x a f a f f a x f a a 2.2 f a f x a f f a x f a a f a f x a f a x f a f x a f a f f a x f a a f a f x a f a a true f a f x a f a f f a x f a a f a f x a f a x f a f x a f f a x f a a true a 0 2 f 2 1 f 2 1 0 f a f x a f a x f a f x a f a f f a x f a a f a f x a f a f f a x f a a f a f x a f a x f a f x a f a f f a x f a a true 2 1 a 0 1 0 f 2 0 1 0 1 1 0 1 0 0 2 0 0 f 2 0 0 1 1 2 0 0 f a f x a f a f f a x f a a f a f x a f a f f a x f a a f a f x a f a f f a x f a a true 2 1 a 0 89133 1 f 2 0 1 0 0 1 0 1 0 0 2 44566 0 f 2 0 0 1 0 2 0 0 f a f x a f a f f a x f a a f a f x a f a a false NaTT certifiable-1.6