The Logikus interactive development environment (IDE) lets you experiment with logic programming. You can launch the environment by running the LogikusIde class:
> java sjm.examples.logic.LogikusIde
The LogikusIde class launches a Swing-based user interface that provides a programming area, a query area, and an area for results. When the IDE comes up, you can enter the program and query shown in Figure 13.1. If you do not want to type in the data, you can find the file starred.txt on the CD and copy and paste its contents into the program area. (This file actually lists 68 of James Cagney's films , four of which appear in Figure 13.1.)
Figure 13.1. The Logikus interactive development environment. The class that is running here is LogikusIde , although it titles itself "Logikus".
With the program in place as Figure 13.1 shows, you can experiment with the Next and Rest buttons. These buttons ask the query to prove itself by unifying with the facts in the program.
