2nd cons1 X cons Y Z Y 2nd cons X X1 2nd cons1 X activate X1 from X cons X n__from n__s X from X n__from X s X n__s X activate n__from X from activate X activate n__s X s activate X activate X X 2.2 2nd cons X X1 activate X1 activate n__s X activate X activate n__s X s activate X activate n__from X from activate X 2nd cons X X1 2nd cons1 X activate X1 activate n__from X activate X true 2nd cons X X1 2nd cons1 X activate X1 false 2nd cons X X1 activate X1 false activate n__from X activate X activate n__s X activate X true s 1 0 activate 1 0 n__from 1 1 1 activate 1 1 0 2nd 1 0 n__s 1 1 1 cons1 2 0 from 1 0 s 1 0 2nd 1 0 from 1 0 cons 2 0 activate n__from X from activate X false activate n__s X s activate X false NaTT certifiable-1.6