================================================================= Logtalk - Object oriented extension to Prolog Release 2.19.1 Copyright (c) 1998-2004 Paulo Moura. All Rights Reserved. ================================================================= To load all entities in this example compile and load the loader file: | ?- logtalk_load(loader). You will need to load the objects in the roots and relations examples. You will also need to load the following files in the library directory: events_loader, types_loader, metapredicates_loader, and hierarchies_loader. Alternatively, you may load the library all_loader file to load all library entities. This folder contains an example of representation and handling of relations using events. We have instances of class brick and a binary brick_stack relation between the bricks. Every time we move a brick, we want the bricks on top of it to move along. If we break the stack by moving a middle brick, we want to automatically destroy the corresponding relation tuple. It's instructive to use the event debugger in the Logtalk library (loader file debugging_loader.lgt) to better understand this example. Set spy points in all brick instances and then activate the debugger.