diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index 94c1b9c..b4675d6 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -35,9 +35,9 @@
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                 "file": "Concurrent Systems/slides/class 4.pdf",
                 "page": 17,
-                "left": -27,
-                "top": 78,
-                "zoom": 0.5754156769596199
+                "left": -36,
+                "top": 91,
+                "zoom": 0.4133016627078385
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               "icon": "lucide-file-text",
               "title": "class 4"
@@ -196,8 +196,7 @@
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     "direction": "horizontal",
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-    "collapsed": true
+    "width": 364.5
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   "left-ribbon": {
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@@ -218,6 +217,7 @@
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   "active": "6edd4157a160e462",
   "lastOpenFiles": [
+    "Concurrent Systems/notes/images/Pasted image 20250317100456.png",
     "Concurrent Systems/notes/4b - Monitors.md",
     "Concurrent Systems/notes/4c - Dining Philosophers.md",
     "Concurrent Systems/slides/class 4.pdf",
@@ -263,7 +263,6 @@
     "Foundation of data science/notes/3.2 LLM generated from notes.md",
     "Foundation of data science/notes/2 Linear Regression.md",
     "Biometric Systems/notes/6. Face recognition 2D.md",
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diff --git a/Concurrent Systems/notes/4c - Dining Philosophers.md b/Concurrent Systems/notes/4c - Dining Philosophers.md
index d4c017d..6bcb9f9 100644
--- a/Concurrent Systems/notes/4c - Dining Philosophers.md	
+++ b/Concurrent Systems/notes/4c - Dining Philosophers.md	
@@ -1,6 +1,7 @@
 The first real practical example of a concurrent system.
-
 - $N$ philosophers seated around a circular table
 - one chopstick between each pair of philosophers
 - a philosophers must pick up its two nearest chopsticks in order to eat
-- a philosoph
\ No newline at end of file
+- a philosopher must pick up first one chopstick, then the second one, not both at once
+![[Pasted image 20250317100456.png|100]]
+
diff --git a/Concurrent Systems/notes/images/Pasted image 20250317100456.png b/Concurrent Systems/notes/images/Pasted image 20250317100456.png
new file mode 100644
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