YES!  If my article on SGML architectures (see http://www.techno.com)
doesn't make that point clear, I feel duty-bound to underline David's
remark.  HyTime is only one possible base architecture.  Other
architectures can inherit features of HyTime if desired, but there is
no requirement that they do so.
Best regards,
--Steve
             Steven R. Newcomb   President
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