diff --git a/4a1s/MFES/PL - Aula 4.md b/4a1s/MFES/PL - Aula 4.md
index 0942345..0f4a965 100644
--- a/4a1s/MFES/PL - Aula 4.md	
+++ b/4a1s/MFES/PL - Aula 4.md	
@@ -69,24 +69,30 @@ pred inv3 {
 	
 	//or
 	all x :User, y :Photo | x in sees.y implies y in x.follows.posts + Ad
+	
+	//or
+	all x :User, y :Photo | y in x.sees implies y in x.follows.posts + Ad
+	
+	//or
+	all x :User | x.sees in x.follows.posts + Ad
 }
 
 
 pred inv4 {
 	// If a user posts an ad then all its posts should be labeled as ads. 
-	
+
 }
 
 
 pred inv5 {
 	// Influencers are followed by everyone else.
-
+	all x: Influencer | follows.x = User-x
 }
 
 
 pred inv6 {
 	// Influencers post every day.
-
+	all x: Influencer, y : Day | x.posts.date = y
 }