lab4.md

@@ -16,10 +16,10 @@ For this lab, we will only use the SPARQL part.
 The following command will start the database (you should add it to your screen):
 
 ```bash
-ros2 run ros2_kdb server
+ros2 run ros2_kdb server --ros-args -p db_port:=101XX 
 ```
 
-The database server is very verbose, you can generally ignore what is printed in the terminal.
+Replace XX with your group number. The database server is very verbose, you can generally ignore what is printed in the terminal.
 
 You can reset the content of the database with (you need to stop the database first):