# Proof that the Lascoux-Schützenberger involutions satisfies the braid-relations

I am interested in the Lascoux-Schützenbereger involutions $$\theta_i$$, defined on semistandard Young tableaux. See this paper for definitions, page 4. These involutions satisfy the braid relations:

(i) $$\theta_i^2 = \text{Id}$$

(ii) $$\theta_i\theta_j\theta_i=\theta_j\theta_i\theta_j$$, for $$\mid i-j \mid=1$$

(iii) $$\theta_i\theta_j=\theta_j\theta_i$$, for $$\mid i-j\mid > 1$$.

It is clear that $$(i)$$ and $$(iii)$$ holds. However, I do not know how to prove $$(ii)$$ and I cannot seem to find a reference for this fact that is not the original article by Lascoux and Schützenberger, which is in French (my French is not that great, unfortunately). Does anyone know another reference and/or a proof of this?

EDIT: Changed notation from $$s_i$$ to $$\theta_i$$ since this is this notation used in the link.

• There are a lot of notations for a lot of involutions in the referenced paper, which is the one denoted in the OP by $s_k$, is it the $\theta_k$ introduced on page 4 after the Cor. 2.2? – dan_fulea Oct 24 '18 at 17:43
• Yes, you are right! I clarified the OP. – Joakim Uhlin Oct 24 '18 at 18:12

I have found another reference: Theorem $$5.6.3$$ in Algebraic Combinatorics on Words by M. Lothaire.