Reverse Polish Notation

This is a very easy to program way of entering mathematical expressions into a computer. It comes under other names, too. PostScript is built on this concept.

A complicated function is built of a series of instructions. An instruction can be either

This is all! Now you only have to know that within Grafix the function argument is always called x, and the parameters p0, ..., p19.
Note that the operators +, -, *, /, ^ (raising to a power) require 2 operands, whereas neg (change sign), inv (take reciprocal) and all algebraic functions like exp, ln, abs,sin, ... require only 1 operand.