diff --git a/test/sierpinski/p.ml b/test/sierpinski/p.ml
index bc5f0be1db4acc8a7e8054baa13f892a593e5609..5fa45cefe91413b8421fbb9c0524ba5db9b73c11 100644
--- a/test/sierpinski/p.ml
+++ b/test/sierpinski/p.ml
@@ -1,4 +1,9 @@
-(* Time-stamp: <modified the 03/07/2023 (at 16:19) by Erwan Jahier> *)
+(* Time-stamp: <modified the 10/07/2023 (at 11:36) by Erwan Jahier> *)
+
+(* Draw the Sierpinski triangle using Wolfram cellular automata
+
+https://mathworld.wolfram.com/ElementaryCellularAutomaton.html
+*)
 
 let rule_nb = 126 (* Sierpinski rule *)
 let _ = assert( 0 <= rule_nb  && rule_nb <256 )