To start the program, the query ‘colour’ is run: type
into TkECLiPSe’s query entry window, followed by the
return key. The program should run, and display the map to be coloured in a
window, which is then coloured, arriving at the
incorrect solution as shown previously. The program uses
the standard ‘generate-and-test’ method, so you will see colour flashing in
the countries as the program tries different colours for them.
The map display has two buttons: pressing More will cause the program to find an alternate way of colouring the map. Pressing Done will end the program and return control to ECLiPSe. You can press More to get more solutions and see that the program returns more solutions that colour countries 3 and 4 to the same colour (along with some that are correct).
Press Done to finish the execution. We will now debug this program.