nats cons 0 n__incr n__nats pairs cons 0 n__incr n__odds odds incr pairs incr cons X XS cons s X n__incr activate XS head cons X XS X tail cons X XS activate XS incr X n__incr X nats n__nats odds n__odds activate n__incr X incr activate X activate n__nats nats activate n__odds odds activate X X 2.2 activate n__nats nats odds incr pairs odds pairs activate n__incr X activate X activate n__odds odds tail cons X XS activate XS incr cons X XS activate XS activate n__incr X incr activate X true tail cons X XS activate XS false activate n__incr X incr activate X incr cons X XS activate XS activate n__odds odds odds incr pairs activate n__incr X activate X true Failed! NaTT certifiable-1.6