[ a b c ]---< a>b?>---(Y)---[ ab c ]---< b>c?>---(Y)-------------------------------------[ abc ]
| \---(N)---[ a cb ]---< a>c?>---(Y)---[ acb ]
| \---(N)---[ cab ]
\---(N)---[ ba c ]---< a>c?>---(Y)--------------------------------------[ bac ]
\---(N)---[ b ca ]---< b>c?>---(Y)-----[ bca ]
\----(N)----[ cba ]