g h x1 g f s x1 f s s s x1 h f s h x1 f h x1 h f s h x1 h x1 x1 f f s s x1 s s s f f x1 b a x1 a b x1 a a a x1 b a a b x1 b b b b x1 a x1 2.2 f s s s x1 f s h x1 a a a x1 b a a b x1 f h x1 f s h x1 a a a x1 b x1 f f s s x1 f x1 f h x1 h f s h x1 g h x1 g f s x1 a a a x1 a a b x1 f f s s x1 f f x1 b a x1 b x1 b b b b x1 a x1 f s s s x1 h x1 f s s s x1 h f s h x1 a a a x1 a b x1 g h x1 f s x1 b a x1 a b x1 true g h x1 g f s x1 true Failed! NaTT certifiable-1.6