diff --git a/models/Application_examples/Tic_Tac_Toe.mp b/models/Application_examples/Tic_Tac_Toe.mp
index 19c32ba64f50e98f23ac571e64090f28c4657f54..a732686b05187ace4a9e065923eee29c7bb52747 100644
--- a/models/Application_examples/Tic_Tac_Toe.mp
+++ b/models/Application_examples/Tic_Tac_Toe.mp
@@ -175,10 +175,10 @@ DO
 OD;
 COORDINATE $second_move:
  (
-     	O_chooses_remnant_next_to_X_on_first_turn           |
+      O_chooses_remnant_next_to_X_on_first_turn           |
       O_chooses_remnant_NOT_beside_an_X_on_first_turn       |
-     	O_chooses_corner	                                      |
-     	O_chooses_center
+      O_chooses_corner                                        |
+      O_chooses_center
  )
 DO
 	ADD SAY("SECOND MOVE OF THE GAME.") PRECEDES $second_move;