That's not the sense of "depends on" that applies here. It's a textual relationship- in this case, I believe the last commit would depend on the second, which w

That's not the sense of "depends on" that applies here. It's a textual relationship- in this case, I believe the last commit would depend on the second, which would depend on the first. If you're familiar with CRDTs, they're closely related. Patches store enough information to commute, so a given state (e.g. a branch) can be described purely by a set of patches.