0P26 Corollary 4.11 (Khovanov). Given b,b′∈Bnb,b^{\prime}\in B_{n} and r∈{1,…,n−1}r\in\{1,\ldots,n-1\}, we have t1−1/2t21/2Ybσr−1b′+t11/2t2−1/2Ybσrb′=−1(t1−1/2−t11/2)Ybb′.t_{1}^{-1/2}t_{2}^{1/2}Y_{b\sigma_{r}^{-1}b^{\prime}}+t_{1}^{1/2}t_{2}^{-1/2}Y_{b\sigma_{r}b^{\prime}}=\sqrt{-1}(t_{1}^{-1/2}-t_{1}^{1/2})Y_{bb^{\prime}}.