On Sun, February 22, 2009 3:49 pm, Christoph LANGE wrote: > On Sunday 22 February 2009 16:31:43 Professor James Davenport wrote: >> > an explicit markup for abbreviated units would make sense, as it would >> > facilitate parsing. On the other hand, one could argue that this is a >> > subproblem of the larger problem of parsing presentation markup back >> > to content markup -- a problem that has not yet been solved >> > sufficiently. >> >> AGREED (but why make it harder by adding this). Our (Davenport/Naylor) >> reasoning went roughtly like this (as far as I can reconstruct it). <snip> >> Of course, you're welcome to disagree with any step of this reasoning. > > I largely agree that this is a more pragmatic solution of the problem. > > James, I think you are aware of that, but for the sake of completeness, > allow > me to note the following about (*): Our notation definitions do not say > that > "p" is an "alternative rendering" of arith1#divide, but that we render the > complete expression (divide mile hour) as "mph". If we had a parser for Agreed in this direction. > applying these notation definitions in reverse, parsing "mph" back to > (divide > mile hour) would still work, as long there is no other notation definition > in the knowledge base that renders something else to "mph". The problem is that,in the reverse direction, 'm' as a child of 'p' has to parse as miles, whereas 'm' as a child of '/' has to parse as metres - think of 'm/s'.
Backwards compatibility with ad-hoc ery is a pain in the neck! James Davenport Visiting Full Professor, University of Waterloo Otherwise: Hebron & Medlock Professor of Information Technology and Chairman, Powerful Computing WP, University of Bath OpenMath Content Dictionary Editor IMU Committee on Electronic Information and Communication _______________________________________________ Om mailing list [email protected] http://openmath.org/mailman/listinfo/om
