a__f X g h f X mark f X a__f mark X mark g X g X mark h X h mark X a__f X f X 2.2 mark f X mark X mark h X mark X mark f X a__f mark X true mark h X mark X mark f X mark X true h 1 1 1 a__f 1 0 f 1 1 1 mark 1 1 0 mark 1 0 a__f 1 0 g 1 0 mark f X a__f mark X false NaTT certifiable-1.6