Your Prolog program has to ask for the description of the movable objects. N is the bot's unique number, X and Y give the bot's position. Angle is how far the bot is turned from the x-axis. Holding is nothing if the bot isn't holding anything, otherwise it is the number of the bar the bot is holding. Speech is the bot's speech string.
Bars also have unique identifiers.
They are described by the x-y position of their centres and their angle. Every file containing a Prolog program that controls a bot must have a start predicate. After that, your program takes control. You are responsible for sending commands to Botworld. For example, the following program instructs your bot to say that it is going to the bar that has the same number as your bot go to the bar grab the bar stop saying anything detach your program from Botworld.