TExpress is a component that I wrote for my own purposes as one
of the backbones for interactive math applications.
It is a component wrapper for an expression evaluator that I have worked
on (and off) over the last 9 years, originally written in Turbo Pascal.
You can still easily convert it to be used with TP6 or 7 by just using
the object OParse defined in pars.pas.
*What is does
It evaluates expressions for functions depending on up to three
variables and up to 6 parameters, but it is a bit unusual.