Foley的笔记

\[ \begin{aligned} &\Phi_A\otimes\Phi_B\otimes\mathbb{1}_P\Big[\mathsf{M}_{a|x}\otimes\mathsf{N}_{b|y}\otimes\mathbb{1}_P\,|\psi\rangle_{ABP}\Big]\\ &\qquad=\Big(\mathsf{M}'_{a|x}\otimes\mathsf{N}'_{b|y}\,|\psi'\rangle_{A'B'}\Big)\otimes|\xi\rangle_{\bar{A}\bar{B}P} \end{aligned} \]