Ask for the syntax of representing operators in Common-Lisp

Hello,

>  In order to write the compiler, I need to know exactly about the abstract
> syntax to parse the above file, or at least the syntax to parse the part
> representing the expression "((MPLUS SIMP)
>             ((MTIMES SIMP) ((RAT SIMP) 1 2) ((MEXPT SIMP) $X 2))
>             ((MTIMES SIMP) ((RAT SIMP) 1 3) ((MEXPT SIMP) $X 3))))

Not sure what you want to do, but working with the S-expression
is probably the right thing to do if you need to manipulate the
expression -- it is essentially a parse tree. Maybe you can find
a S-expression parser already written in the language of your choice.

About internal representation of Maxima expressions, see:

http://maxima.sourceforge.net/wiki/index.php/outline%20of%20Maxima%20internals
http://maxima.sourceforge.net/wiki/index.php/Maxima%20internals

HTH
Robert Dodier