第二次使用Markdown编辑文件测试

$$ P(\beta_t|\beta_{t+1},\theta,\tilde{Y}_t)=N(E(\beta_t|\beta_{t+1},\theta,\tilde{Y}_t),Var(\beta_t|\beta_{t+1},\theta,\tilde{Y}_t)) $$
        $$ E(\beta_t|\beta_{t+1},\theta,\tilde{Y}_t)=\beta_{tt}+V_{tt}(V_{tt}+Q)^{-1}(\beta_{t+1}-\beta_{tt}) $$
        $$ Var(\beta_t|\beta_{t+1},\theta,\tilde{Y}_t)=V_{tt}-V_{tt}(V_{tt}+Q)^{-1} $$

$$ P(\beta_t|\theta,\tilde{Y}_t)=N(\beta_{tt},V_{tt}) $$
                $$ \beta_{tt}=E(\beta_t|\theta,\tilde{Y}_t) $$
                $$ V_{tt}=Var(\beta_t|\theta,\tilde{Y}_t) $$

Step 1: Draw $\beta_T$ from $P(\beta_T|\theta,\tilde{Y}_T)$
Step 2: Draw $\beta_{T-1}$ from $P(\beta_{T-1}|\beta_T,\theta,\tilde{Y}_{T-1})$