diff --git a/Concurrent Systems/notes/Lezione1.md b/Concurrent Systems/notes/Lezione1.md
index 8ba2f1e..61cfb0d 100644
--- a/Concurrent Systems/notes/Lezione1.md	
+++ b/Concurrent Systems/notes/Lezione1.md	
@@ -181,4 +181,15 @@ b) `AFTER_YOU = 1`, this is possible only with the following interleaving:
 
 - It is possible tho that p1 locks again:
 	- if p0 reads `F[1]` before p1 locks, then p0 wins (waiting 1)
-	- otherwise p1 sets A_Y to 1 and suspends in its wait (`F[0] = up AND A_Y = 1`), p0 will eventually rea
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+	- otherwise p1 sets A_Y to 1 and suspends in its wait (`F[0] = up AND A_Y = 1`), p0 will eventually read `F[1]` and win (waiting 1).
+
+### Peterson algorithm ($n$ processes)
+- FLAG now has $n$ levels (from 0 to n-1)
+	- level 0 means down
+	- level >0 means inv
+- Every level has its own AFTER_YOU
+
+```
+Initialize FLAG[i] to 0, for all i
+
+lock
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