diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index a55dfd1..7e61067 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -240,9 +240,9 @@
   },
   "active": "84845736e00d5c98",
   "lastOpenFiles": [
-    "Pasted image 20250414102733.png",
     "Concurrent Systems/slides/class 12.pdf",
     "Concurrent Systems/notes/12 - bastaaaaaaaa.md",
+    "Pasted image 20250414102733.png",
     "Concurrent Systems/notes/11 - LTSs and Bisimulation.md",
     "Concurrent Systems/slides/class 11.pdf",
     "Pasted image 20250414093017.png",
@@ -257,7 +257,6 @@
     "Concurrent Systems/notes/images/Pasted image 20250408091924.png",
     "Concurrent Systems/notes/images/Pasted image 20250408093840.png",
     "Concurrent Systems/notes/images/Pasted image 20250408094749.png",
-    "Concurrent Systems/notes/images/Pasted image 20250408092853.png",
     "Concurrent Systems/notes/10 - Implementing Consensus.md",
     "Concurrent Systems/notes/2 - Fast mutex by Lamport.md",
     "Concurrent Systems/notes/4 - Semaphores.md",
diff --git a/Concurrent Systems/notes/12 - bastaaaaaaaa.md b/Concurrent Systems/notes/12 - bastaaaaaaaa.md
index d46bb4a..0f6cecc 100644
--- a/Concurrent Systems/notes/12 - bastaaaaaaaa.md	
+++ b/Concurrent Systems/notes/12 - bastaaaaaaaa.md	
@@ -17,3 +17,8 @@ When two processes synchronize, an external observer has no way of understanding
 
 The set of actions we shall consider is: ![150](../../Pasted%20image%2020250414102733.png)
 
+It is also useful to force some processes of the system to synchronize between them (without the possibility of showing to the outside some actions)
+
+The restriction operator P\a restricts the scope of name a to process P (a is visible only from within P)
+
+This is similar to local variables in a procedure of an imperative program
\ No newline at end of file