diff --git a/docs/10.md b/docs/10.md
index 38b0b57ee6e5e220e3320e00455fc5fe739e9ce1..1bb27084eec556e6861ce81ed369a1a55f3f1751 100644
--- a/docs/10.md
+++ b/docs/10.md
@@ -689,4 +689,14 @@ $$
 \lVert\overline{G}\rVert_{1} = \lVert (I-\gamma P_{\pi'})^{-1} \rVert_{1} = \lVert \sum_{t=0}^{\infty}\gamma^{t} P_{\pi'}^{t} \rVert_{1} \leq \sum_{t=0}^{\infty} \gamma^{t} \lVert P
 _ {\pi'} \rVert_{1}^{t} = \frac{1}{1-\gamma}，
 \tag{14}
+$$
+
+接下来限制 $\lVert \Delta d^{\pi} \rVert_{1}$。
+
+$$
+\lVert \Delta d^{\pi} \rVert_{1} = \sum_{s'} |\sum_{s} \Delta(s'|s)d^{\pi}(s)|
+$$
+
+$$
+\leq \sum_{s',s}|\Delta(s'|s)|d^{\pi}(s)
 $$
\ No newline at end of file