diff --git a/src/main.rs b/src/main.rs
index 8111819..90adc6d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -29,6 +29,7 @@ fn check_map(r: &robot::Robot, w: &world::World) -> Result<(), String> {
         Ok(())
     }
 }
+/// Check if the robot collide with another one at the given position.
 fn check_collisions(
     r: &robot::Robot,
     w: &world::World,