Proof Designer is a Java applet that writes outlines of proofs in elementary set theory, under the guidance of the user. It is intended to help students learn to write proofs.

The version of Proof Designer on this page is out of date. There is a new JavaScript version of Proof Designer. To get to it, click here.

A version of Proof Designer as a stand-alone application (not an applet) is under development. It includes the ability to save and load proof sessions, as well as a number of other enhancements. You can find it here. The new version is being developed by Moez AbdelGawad.

If you want to try to use the old, applet version of Proof Designer, it is still available on this page. Before you can use Proof Designer, you may have to make some adjustments to the configuration of your computer or browser. The documents listed below will help you set up your computer to use Proof Designer and then learn how Proof Designer works.

- Setting up your computer to use Proof Designer.
- Quick Start. This document will lead you through an example that illustrates how Proof Designer works.
- Proof Strategies.
This document suggests strategies for writing proofs. For each strategy,
it also explains what command to give in Proof Designer if you want to
use that strategy in a proof. For a more complete explanation of these
strategies, see my book
*How To Prove It*, published by Cambridge University Press. - Proof Designer Instructions.
- Typing expressions in Proof Designer.
- Suggested problems to do in Proof Designer.

It may take a minute for Java to start up, and for the Proof Designer applet to be loaded. Once the applet has been loaded, a button labeled “Write a Proof” should appear below this line. If it does not appear, refer to the instructions for setting up your computer to use Proof Designer.