User blog comment:PsiCubed2/How to make Deedlit's Mahlo-level notation more intuitive/@comment-35470197-20180807000338/@comment-30754445-20180809094205

Well, this is going to take some time to make heads or tails of (if I ever succeed in it at all).

I can make one observation, though, right now:

You say that Deedlit's notation is very different from Rathjen's. I think we can safely assume that this is not due to some oversight on his part. The differences are too great.

It is also clear that Rathjen's notation is much more complicated and more difficult to understand. So obviously, Deedlit tried to "re-notate it" in a way that's easier to follow.

So the first clue I'll investigate, is the PTO of KPM. We know how Rathjen notates it, and we know how Deedlit notates it. So let's try to "reverse engineer" this example, in order to see whether we can figure out the actual transformation Deedlit had in mind.