FPARSER  (UNIT) LIBRARY REFERENCE

  Version     - 0.00

  File        - FPARSER.PAS

  Copyright   - None. Public Domain.

  Author      - Keith S. Brown (except where otherwise noted)
                Surface mail:              Email:(brown@smd4.jsc.nasa.gov)
                  K.Brown
                  Code:NASA/JSC/ES64
                  Houston, TX 77058 (USA)  Voice:713-483-8952

  Purpose     - 1. Translate an infix expression to tokenized RPN.
                2. Execute a tokenized RPN expression.

  Language    - Borland International's Turbo Pascal V:4.x+ for MS-DOS

  Remarks     - Handles standard Pascal computational assignment expressions.
                With some differences, ie.:

               as per Ada, numeric values may contain embedded underscores.

               only the first 63 characters of an identifier are significant

               the semi-colon terminating an expression is optional.

               the extended unary functions "ArcCos", "ArcSin", "Log"
                (base 10), "Sign", "Step", "Tan" are available as well as
                the standard Pascal unary functions "Abs", "ArcTan", "Cos",
                "Exp", "Ln", "Round", "Sin", "Sqr", "Sqrt", "Trunc".

               the extended binary operators "^" (as in x^3, cube of x) are
                available as well as the standard Pascal binary operators
                of "+", "-", "*", "/", "DIV", and "MOD".

               the extended trinary functions:
                "Gate(x,cntr,wide:REAL):REAL;"     (rectangular pulse),
                "Gaus(x,cntr,varia