[ros-users] Basic Odometry/tf information

Hello,
We have a basic robot setup and we are trying to do mapping. I am having a
hard time understanding how transforms work. We have one laser range finder
and one source of odometry. Based on the TF setup tutorial, it looks like I
should have base_link as the parent and base_laser as the child and also
base_link as the parent and odom as the child. However, based on the odom
tutorial, it looks like i should have odom as the header and base_link as
the child. Which way is correct?