Box-ball systems and Robinson-Schensted-Knuth correspondence

The box-ball system is studied from the viewpoint of combinatorics of words and tableaux. Each state of the box-ball system can be transformed into a pair of tableaux $(P,Q)$ by the Robinson-Schensted-Knuth correspondence. In the language of tableaux, the $P$-symbol gives rise to a conserved quantity of the box-ball system, and the $Q$-symbol evolves independently of the $P$-symbol. The time evolution of the $Q$-symbol is described explicitly in terms of the box-labels.