I'm trying to display the modifications in the last commit. To de so I'm trying to use gl history.

The verbose option provides a nice display of changes.
Unfortunately the -l (limit) option is apparently limited.

It seam that it always start counting history from the first commit. I couldn't find how to display the history starting from a specific commit, or HEAD - x commits.
An op

This is confusing and error prone. It should be called "created" to be consistent with the rest of the CLI and Python API.

The first episode is more a description of "a" version control system, rather than of Git. I think that's useful as this is the first exposure of many learners to the concept. Also, the model based on diffs in not completely accurate for Git. A compromise to be both accurate and keep it simple could be to change the second objective to reflect this. So, what about?

Understand the basics