Forgive me, but why is the TreeNotation/jtree library the right place to craft a new "rigorous" mathematics language?
First, jtree is a bit orthogonal as that’s just an implementation. The github issue is there for convenience, it’s arbitrary.
The reason for tree notation is that it’s a level up from binary. Binary notation does not give you the ability to define new symbols. Tree notation is a 2d binary. You can define new abstractions. It is a bridge between human and machine languages.
Take any concept in mathematics, such as “derivative”. How would you define such a concept, starting only from 1s and 0s? Tree notation gives you a method to do that, in a way that’s not only efficient (noiseless), but also gives you practical tools, like complexity counting.