is what is happening is that the reader parses "{...}" into a table object with a as a key and (- 5 4) as the value, and then the Arc compiler would, when it was passed a table object to compile, recursively compile the values of the table?
If so, then the part I wasn't getting was that the reader would return an actual table object which the Arc compiler would then work on... I hadn't thought of that approach.
