diff --git a/Concurrent Systems/notes/11 - non so cosa faremo oggi.md b/Concurrent Systems/notes/11 - non so cosa faremo oggi.md
index 80fecce..2aeb50b 100644
--- a/Concurrent Systems/notes/11 - non so cosa faremo oggi.md	
+++ b/Concurrent Systems/notes/11 - non so cosa faremo oggi.md	
@@ -23,3 +23,13 @@ The essence of the difference is WHEN the decision to branch is taken
 -  language equivalence gets rid of branching points
 	- it is too coarse for our purposes!
 
+### LTSs
+In concurrency theory, we don’t use finite automata but Labeled Transition System (LTS). The main differences between the two formalisms are:
+- automata usually rely on a finite number of states, whereas states of an LTS can be infinite
+- automata fix one starting state, whereas in an LTS every state can be considered as initial (this corresponds to different possible behaviors of the process)
+- automata rely on final states for describing the language accepted, whereas in LTS this notion is not very informative
+
+Fix a set of action names (or, simply, actions), written N.
+>[!note] LTS formal definition
+>A Labeled Transition System (LTS) is a pair (Q, T), where Q is the set of states and T is the transition relation (T ⊆ Q × N × Q).
+