Thanks for your feedback, Robert, and to the link to your article. You and I are talking about natural language at different levels of abstraction. I agree with the abstract ideas that you present in your article, but my interest is in how to apply them to a concrete example like the Playing Card World. I learn more by going from the concrete to the abstract than just by abstract arguments that can't (at least so far) be applied to concrete examples. I have implemented parts of a Playing Card Agent and have worked on designing more, from which I, personally, have learned a lot, especially about the need to model accurately human mechanisms for short-term memory and attention, whether as neural networks or more traditional data structures used in computer programming.