L = E t , ϵ , T [ ‖ v ( ϵ , x 0 , t ) − v θ ′ ( x t , t , { ϕ ( o i < n ) } , { A e m b ( a i < n ) } ) ‖ 2 2 ] {\displaystyle {\mathcal {L}}={{\mathbb {E} }_{t,\epsilon ,T}\left\lbrack {\|{{v{(\epsilon ,x_{0},t)}}-{v_{\theta ^{\prime }}{(x_{t},t,{\{{\phi {(o_{i<n})}}\}},{\{{A_{emb}{(a_{i<n})}}\}})}}}\|}_{2}^{2}\right\rbrack }} (1)