On Mon, 26 Jun 2006, Andre van Tonder wrote:

> As corrobrating evidence, I can mention the syntax-case implementation in
> SRFI-72.  That implementation satisfies declarative descriptions of hygiene.
> However, the implementation technique is based on an "implicitized" version
> of explicit renaming, not marking/substitution.  There are some highly
> obscure corner cases where it behaves differently from the marking algorithm,
> while still satisfying hygiene.  I have to recheck, but I think these
> ambiguities should be resolved by specifying the algorithm as is
> done here (though perhaps a little more detail might be required).

Scratch that.  I checked the purported corner case.  It is not relevant to the
context of the current SRFI.  So, as far as I can tell, the SRFI-72 algorithm
will give the same results as the mark/substitution algorithm.

Regards
Andre