diff --git a/Concurrent Systems/notes/9 - Consensus.md b/Concurrent Systems/notes/9 - Consensus.md
index 313e5c1..235391e 100644
--- a/Concurrent Systems/notes/9 - Consensus.md	
+++ b/Concurrent Systems/notes/9 - Consensus.md	
@@ -192,3 +192,11 @@ mv_propose(i,v) :=
 			return PROP[k]
 	wait forever
 ```
+why wait forever? Because we want to prove that it is wait free, but not because the loop finishes.
+
+##### Validity, Agreement, Integrity, Termination:
+- Let $p_{x}$ the first process that writes a proposal
+- every $p_i$ that participates to the consensus reads the other proposals after that it has written `PROP[i]`
+	- all participants starts their for loops after $p_x$ has written its proposal
+- every $p_i$ that participates to the consensus finds `PROP[x] != ⊥` in their for loop
+- `BC[x]` o
\ No newline at end of file