Superficially this is a colorful variant of dominoes with weird tiles, a simple matching game to play during lunch breaks. But hidden behind this façade are the inference rules of natural deduction, so that every solved level represents a proof of a tautology. This program demonstrates that logical reasoning can be done without any language or symbols, relying purely on the brain's visual capabilities.
If you're interested in the scientific background of the game, you can read the complete article about it (HTML)
If you have have a Java-enabled browser you can click on the screenshot below to play the game online.
You can download the game together with the source code (licensed under the GPL) as a single jar file:
To play the game, just execute the command
java -jar Domino.jar
Depending on your environment, it may even be sufficient to double-click the file in your file manager. You will need a Java Runtime Environment installed on your machine. The program has been tested with versions 1.3.1 and version 1.4.0 on Linux and Windows.
If you want to work with the source code, you need to extract it first. Copy the jar file to a directory of your choice and execute the command
jar xf Domino.jar
This will create the directories domino and META-INF. You can delete the latter. The domino directory contains the compiled .class files and the .java sources. For working with either you need to put the directory domino/.. (i.e. domino's parent directory) into your CLASSPATH. The main class of the program is domino.ui.UITest, so to start the game you can use the command
java domino.ui.UITest
Rebuilding the complete program and building the javadoc documentation is easy if you're in a Unix-style environment with the standard build and shell tools. A simple make should suffice. Note that this has only been tested under Linux.
For more developer info as well as the git repository for this game, visit the SourceForge project.
Copyright (c) 2000-2010 by Matthias Benkmann