diff --git a/assets/section_2.5_1686968005870_0.edn b/assets/section_2.5_1686968005870_0.edn
index 7b27a1c..c843594 100644
--- a/assets/section_2.5_1686968005870_0.edn
+++ b/assets/section_2.5_1686968005870_0.edn
@@ -177,5 +177,17 @@
                           :rects (),
                           :page 39},
                :content {:text "[:span]", :image 1686973691894},
+               :properties {:color "yellow"}}
+              {:id #uuid "648d2d62-f5e5-491f-ae12-e9638ee75f7c",
+               :page 42,
+               :position {:bounding {:x1 35,
+                                     :y1 141.25,
+                                     :x2 647,
+                                     :y2 267.25,
+                                     :width 677.2919999999999,
+                                     :height 507.96853333333326},
+                          :rects (),
+                          :page 42},
+               :content {:text "[:span]", :image 1686973793408},
                :properties {:color "yellow"}}],
  :extra {:page 42}}
diff --git a/assets/section_2.5_1686968005870_0/42_648d2d62-f5e5-491f-ae12-e9638ee75f7c_1686973793408.png b/assets/section_2.5_1686968005870_0/42_648d2d62-f5e5-491f-ae12-e9638ee75f7c_1686973793408.png
new file mode 100644
index 0000000..a7c08be
Binary files /dev/null and b/assets/section_2.5_1686968005870_0/42_648d2d62-f5e5-491f-ae12-e9638ee75f7c_1686973793408.png differ
diff --git a/pages/hls__section_2.5_1686968005870_0.md b/pages/hls__section_2.5_1686968005870_0.md
index a19104b..0bce074 100644
--- a/pages/hls__section_2.5_1686968005870_0.md
+++ b/pages/hls__section_2.5_1686968005870_0.md
@@ -105,4 +105,11 @@ file-path:: ../assets/section_2.5_1686968005870_0.pdf
   hl-color:: yellow
   id:: 648d2cfd-2cef-48d2-b791-e5ac01e43fd8
   hl-type:: area
-  hl-stamp:: 1686973691894
\ No newline at end of file
+  hl-stamp:: 1686973691894
+- [:span]
+  ls-type:: annotation
+  hl-page:: 42
+  hl-color:: yellow
+  id:: 648d2d62-f5e5-491f-ae12-e9638ee75f7c
+  hl-type:: area
+  hl-stamp:: 1686973793408
\ No newline at end of file
diff --git a/pages/总复习2023t1.md b/pages/总复习2023t1.md
index 408ac76..f876ccb 100644
--- a/pages/总复习2023t1.md
+++ b/pages/总复习2023t1.md
@@ -2829,6 +2829,8 @@
 								- Calculating distribution between certain intervals :-> ((648d29b2-c64e-4480-b633-169fe5f0b6cd))
 								  id:: 648d29b8-bd11-4eb6-9240-941c2ff636f1
 								- Calculating negative ones :-> ((648d29da-0535-4dd3-ae79-48b34e047339))
+								- (Some sort of ) linearity :-> ((648d2d62-f5e5-491f-ae12-e9638ee75f7c))
+								-
 								- Example
 									- in specified interval ((648d2c35-041a-4575-b39d-c42c1a6f532f))
 									- without knowing $$\mu$$ and $$\sigma$$: ((648d2cfd-2cef-48d2-b791-e5ac01e43fd8)) #flashcard