Professor James Davenport wrote: > On Wed, 24 Sep 2008, Bruce Miller wrote: > >> Professor James Davenport wrote: >> >>> On Wed, 24 Sep 2008, Paul Libbrecht wrote: >>> >>>> Making them n-ary doesn't solve the classical writing of >>>> a < b > c >>>> which is used quite often still. >>>> >>> Is it? Oh my God .... >>> >> I agree; that's scary! >> OTOH, it is quite common to string different, >> but "consistent", relations together: >> a = b > c = d >= e >> f >> >> Sometimes the consistency is dubious: >> a = b >> approx c >> approx d >> (where the approx is indicating that the rhs has >> been somehow approximated, expanded or whatever). >> I've seen cases where it seemed that the d >> was more likely an approximation of a than c! >> > Indeed so, and therefore it is ahrd to give SEMANTICS to these. > > <snip> And then there's the occasional > >> Indeed; while I do think it is appealing to be able to >> preserve this notational structure, nary relations >> only scratch the surface. Short of a contrived >> multi-relation construct, this situation would >> seem to be best solved (at a MML level) by >> a <semantics> pairing of the desired notation >> and the underlying logic, probably using sharing/id/ref. >> >> > Indeed so, or some other notational method to be invented, but it's a > NOTATION, not SEMANTICS. >
one way to do this is to appeal to a variant notation definition by placing @variant attributes strategically. For instance, if we have the pragmatic a = b = c which would be represented as a = b /\ b=c, then we could have a variant="chaineq" on the [EMAIL PROTECTED] symbol and on the second [EMAIL PROTECTED] symbol, telling the renderer not to render the /\ and for the = not to render the first argument. The only problem I see here is how to get the <mrow>s right. Michael -- ---------------------------------------------------------------------- Prof. Dr. Michael Kohlhase, Office: Research 1, Room 62 Professor of Computer Science Campus Ring 12, School of Engineering & Science D-28759 Bremen, Germany Jacobs University Bremen* tel/fax: +49 421 200-3140/-493140 [EMAIL PROTECTED] http://kwarc.info/kohlhase skype: m.kohlhase * International University Bremen until Feb. 2007 ---------------------------------------------------------------------- _______________________________________________ Om3 mailing list [email protected] http://openmath.org/mailman/listinfo/om3
