Just that abbreviation brings back good memories to a CS practicum in which we needed to write a language parser and virtual world manager in Prolog. Especially

Just that abbreviation brings back good memories to a CS practicum in which we needed to write a language parser and virtual world manager in Prolog. Especially building the memory functionality -- "place the blue ball on top of the red cube", "move the ball to the right" -- was fun, taking into account the vague reference to earlier objects and possible/allowed movements. Man, I need to find that code just to enjoy the memories...