主题
Y=f(i,Si,U,t,Σ)Y = f(i, S_i, U, t, \Sigma) Y=f(i,Si,U,t,Σ)
[iSiUtΣ]\begin{bmatrix} i \\ S_i \\ U \\ t \\ \Sigma \end{bmatrix} iSiUtΣ