Project: calculator-gui
Authors: Michael Kolling and David J. Barnes

This project is part of the material for the book

   Objects First with Java - A Practical Introduction using BlueJ
   Third edition
   David J. Barnes and Michael Kolling
   Pearson Education, 2006


This program is meant to implement a simple pocket calculator.
In its initial version, it is incomplete.

The Calculator and UserInterface classes can be used as they are, but the 
CalcEngine, the bit that does the real calculations, has not been implemented.

It is your task to finish the job. Have fun! 

To start this application (once you have implemented the missing bits) just
create an object of class Calculator.