SUBST vs INLINE, consistent compilation

[Earl A. Killian <EAK at MIT-MC>]

In Common Lisp the macro definition of SWAP would be the same of
as your SUBST, except for some commas (i.e. defmacro handles
normal argument lists).  I don't think Common Lisp needs subst
as another way of defining macros.  Inline functions are,
however, useful.