On Sun, February 22, 2009 1:02 pm, Christoph LANGE wrote: > On Sunday 22 February 2009 04:52:44 Professor James Davenport wrote: >> > More naturally from my point of view is treating [the unit >> abbreviation] >> > problem as a problem of rendering OpenMath to presentation markup. >> For >> > that, our (admittedly, >> >> No - it's a bi-directional problem, I think. If not, then your >> suggestion is at least plausible. > > I see. You're right, so far I've only touched the "content -> > presentation" > direction. When would the other direction apply? Are you talking about > parsing? (E.g. parsing the input given to Jonathan's converter?) Then, Parsing (as in that example) orpossibly re-parsing, hybrid markup etc. > 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). (a) Somehow, we need to connect the bizarre strings mph (and to a lesser extent kmph) with their semantic content. (*) I say bizarre in that 'm' is normally the abbreviation for metres, not miles, and only crops up here (and, though we hadn't coded it, in 'mpg'= "miles per gallon", for fuel efficiency). The point is that these strings are not partof a general pattern: one can't use 'p' as a symbol for division in general. (b) Therefore there needs to be a semantic concept on which to hook this parse. (c) It would be better if this were a well-defined concept (an OMS in this case), rather than a compound object. Of course, you're welcome to disagree with any step of this reasoning. >> > not-yet-standard) approach is defining notations, and we do that by >> > mapping content markup patterns to presentation markup templates. >> That >> > said, we could easily define a "presentation context" "abbreviated" >> > and then map >> > >> > units_imperial1#mile to "mi" >> > units_time1#hour to "hr" >> > (arith1#divide units_imperial1#mile units_time1#hour) to "mph". >> >> Sorry - I don'tseehow this one works. > > Let me give you a concrete example for the latter, in our notation > definition syntax (see the MKM 2008 paper or > http://kwarc.info/publications/papers/KLMMR_NfAD.pdf for details): <snip> > Now assume the content markup (abbreviated in Lisp style) > > (arith1#times > 1 > (arith1#divide > units_imperial1#mile > units_time1#hour)) > > Suppose "times" renders to the "invisible times" symbol. Suppose there is > a general notation definition for "divide" (rendering as a/b): This one > would be > ignored here, as the more specific one given above applies. Then, the > content > markup would render to "1 invisible-times mph", which is what we want. OK - I see how it works in this direction now. > The additional benefit of this approach is, as I believe, the one can use > context-dependent presentation. Think of kilometres per hour, which are > rendered as "kph" in English but as "km/h" in other languages. (Is that > right?) I normally use 'kmph', but I'm not sure how general that is. Next time I wander outside here (i.e. Canada) I'll look more carefully at the road signs.
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
