[justinpombrio]

Yes, I think you understand perfectly. `abandon` was the diagram I struggled the most to draw.

I like the idea of putting the edits on the arrows, but there are a couple senses in which the edit is associated with the change itself rather than an edge between two changes:

1. A change with two parents starts out by merging them, and then it can make edits on top of that merge. If the edits go on an edge instead of on a node, which of the two edges do those changes belong on?

2. If you move a change (e.g. by rebasing it), its diff comes with it. I guess you could say that when you rebase, you're not moving just the node but also the edge from it to its parent?

Even so, diffs on edges feels very right. I may update that diagram.

EDIT: Updated!