I do not know (literally! I do CL, not Scheme) if that would work, but it is a bit of a religious issue dividing the Lisp communities. Indeed, this is one of the reasons I am even looking at Arc, that and that mac works like CL defmacro. And fwiw, those two issues were highlighted by pg as things differentiating Arc and Scheme. Not sure if I am adding anything to the debate, but I get the feeling it either would not work or it would freak out any Schemer finding it in ac.scm. :) I guess another thought might be not to get too caught up in ac.scm since it is implementation and might disappear and become <gasp> an Arc/C or Arc/CL compiler or something.