diff --git a/Algo/Séminaire/Exercices seminaire.md b/Algo/Séminaire/Exercices seminaire.md
index 9cc8721..dea204e 100644
--- a/Algo/Séminaire/Exercices seminaire.md	
+++ b/Algo/Séminaire/Exercices seminaire.md	
@@ -262,6 +262,13 @@ flowchart LR
 A[seq 3] --> B[4*seq2-1] --> C[4*seq1-1] --> D[4*seq0-1] --> E[1] --> F[4*1-1] --> G[4*3-1] --> H[4*11-1]
 ```
 
+## Exercise 4.3
+```Ocaml
+# let geometric n u0 q =
+	let rec geo = function
+	| 0 -> u0
+	|n -> q*geo(n-1) in geo n;;
+```
 ## Exercise 4.5
 ```Ocaml
 let rec add a = function