a b a a b b x1 a a b a b b a x1 2.2 a b a a b b x1 a b a b b a x1 a b a a b b x1 a b b a x1 a b a a b b x1 a a b a b b a x1 a b a a b b x1 a x1 true a b a a b b x1 a x1 true a 1 1 38 b 1 1 1 a 1 1 0 a b a a b b x1 a a b a b b a x1 false a b a a b b x1 a b b a x1 false a b a a b b x1 a b a b b a x1 false NaTT certifiable-1.6