pascal state machine delphi SCRIPT TFPExpressionParser Regular Expression
Parser Regular Expression mathematical
https://wiki.freepascal.org/How_To_Use_TFPExpressionParser
https://wiki.freepascal.org/FPSpreadsheet_tutorial:_Writing_a_mini_spreadsheet_application
pascal script interpreter
torry Components Science Expressions
https://torry.net/pages.php?id=307
http://www.gobestcode.com/html/mathparser.html
https://en.wikipedia.org/wiki/Pascal_(programming_language)