diff --git a/参数/精神.md b/参数/精神.md
index 0e3bcb9..8600587 100644
--- a/参数/精神.md
+++ b/参数/精神.md
@@ -2,4 +2,4 @@
 
 ## 定义
 
-`$ 目标生物 $`
\ No newline at end of file
+`$ \lg\left(\frac{a}{b}\right) $`
\ No newline at end of file