"applying a function to objects in a graph" implies something like: bold(element) and center(element) which yields: <bold><foo /><bar /></bold> <center

"applying a function to objects in a graph" implies something like: bold(element) and center(element) which yields: <bold><foo /><bar /></bold> <center><baz /></center> CSS Selectors can be applied a number of ways (id, class name, parent class name etc) And they can be modified without touching the source HTML. But yeah, that's what AOP is: You specify a function that can be dynamically applied to various pointcuts.