\enableregime[il1]

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\startformula \startalign

\NC Q_{x_T}(H_0)\equiv Q(H_0)\NC=\sum_{H_1,\dots,H_{\tau^*-1}}\left(\prod_{\tau=0}^{\tau^*-1} h_{x_Tx_{T_0}}(H_\tau|H_{\tau+1})\;P_{x_{T_0}}(H_{\tau+1}|H_\tau)\right)\NR

\NC\NC=\sum_{H_1,\dots,H_{\tau^*-1}}\left(\prod_{\tau=0}^{\tau^*-1} h_{x_Tx_{T_0}}(H_\tau|H_{\tau+1})\prod_{\tau=0}^{\tau^*-1}P_{x_{T_0}}(H_{\tau+1}|H_\tau)\right)\NR

\NC\NC=\Epsilon_{P_{x_{T_0}}}\left[\prod_{\tau=0}^{\tau^*-1} h_{x_Tx_{T_0}}(H_\tau|H_{\tau+1})\right]\NR

\stopalign \stopformula

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