formatting of numbered variables

[jvoigtlaender]

Is there a way to have the variable names introduced by renumbering, like A#1

look more like a LaTeXed $A_1$ would look, i.e., with subscripting?

[jvoigtlaender]

An alternative, with the same aim of reducing visual clutter, would be to write out A' instead of A#1, and A'' instead of A#2 etc.

That could become a bit bothersome with A#8 etc., but maybe such large numberings do not typically appear in the trees we want drawn.

Another aspect is that A' is actually a syntax error if trying to submit an intermediate query (displayed in the tree) including such a variable to a Prolog system. But so is A#1. A slight difference is that the quote ' might actually appear in a Prolog query (but maybe not in "our" interpreter here), though with a different role.