Consider the following inequality of Lemma 1 arising in [The law of large numbers for quantum stochastic filtering and control of many-particle systems][1] : $$\Big|tr(L\gamma LB) - \frac{1}{2}tr(B(L\gamma + \gamma L))tr(BL + \gamma L) + tr(B\gamma)tr(BL)tr(\gamma L) \Big| \leq 5||L||^2 tr\big((Id-\gamma)B\big),$$ where $\gamma$ is a ($n\times n$) **density matrix of rank one** (see https://en.wikipedia.org/wiki/Density_matrix for the definition of density matrix), $B$ is a **density matrix** and $L$ a **hermitian matrix**. My question is whether the above inequality holds (up to some constant in front of $tr\big((Id-\gamma)B\big)$) by assuming only that $\gamma$ is a **density matrix** (with the assumptions on $\gamma, L$ unchanged)? [1]: https://link.springer.com/article/10.1134/S0040577921070084