Prog i need your wisdom

No this isn't a joke, or a meme or a fad or whatever you think it is. It just a
regular programming problem.

I'm making a ASCII-art math generator. So you can input in your document
Maxima-notation math and get a corresponding representation. Example:

>Integrate(x^2,x,0,5)

  5 __
   / 2
 _/ x  dx
 0

While a got the AST right. When making the representation on ASCII-text I hit a
problem. The inner-term can change the structure of the outer ones, so this
isn't straight forward

>integrate(x,x,0,5)
>integrate(x+3/2,x,0,5)

  5 __
   / 
 _/ x  dx
 0           

   5 ______
    /   3
   /x + -   dx
 _/     2
 0

 Which is the simplest approach to this?

 Pd: I am not telling in what I'm implementing it so it doesn't derail.

oh...so it only shows the last line...simply put, the fieldset has an associated buffer, when you call setText you SET the contents of that buffer, when you call println you APPEND something to some buffer, in this case to a file stream shown somewhere

why are you using something graphical if you didn't get there yourself