Thanks. --Robert
> -----Original Message----- > From: Paul Libbrecht [mailto:[email protected]] > Sent: Wednesday, February 11, 2009 4:08 PM > To: Robert Miner > Cc: OM3 Mailing list; [email protected] Group WG > Subject: Re: trouble with container markup example > > You are absolutely right Robert, > > and I fear that both OpenMath and MathML content are having > subset_suchthat (the set of things inside a reference set such that > some condition holds) but miss > > set_of_expressions_such_that > > To serve the purpose below ( {[0,x] | x in R} ) > and many others where basically one constructs a set by applying > functions to a few other sets. I think { [x,y] | x in R and y in R } > is even more difficult. > > Maybe James Davenport or Olga can help here. > > paul > > Le 11-févr.-09 à 22:59, Robert Miner a écrit : > > > > > Thanks. Yes, it was supposed to be a set of intervals. In ASCII, > > {[0,x] | x in R} > > > > But I don't think your formulation can be right either. The > > description of http://www.openmath.org/cd/set1.xhtml#suchthat says > > the second argument is an expression returning a Boolean argument. > > My reading was the suchthat is used to pick a subset out of another > > set. If we say W is the set of all intervals of the real line, then > > I could do > > > > <apply> > > suchthat > > W > > {expression that returns true for w in W if one of the endpoints is > > 0} > > </apply> > > > > or something like that. Basically, I guess I'm concluding this is > > just a bad example because it is so hard to understand, and I'm > > going to switch it to something easy. > > > > --Robert > > > >> -----Original Message----- > >> From: Paul Libbrecht [mailto:[email protected]] > >> Sent: Wednesday, February 11, 2009 3:50 PM > >> To: Robert Miner > >> Cc: David Carlisle; [email protected]; member- > [email protected] > >> Subject: Re: trouble with container markup example > >> > >> Robert, > >> > >> So we're talking about a set of intervals, right? > >> (at first I was reading this as yet another expression of an > interval > >> itself!) > >> > >> I would agree that adding the domainofapplication element would be > >> cleaner but it does not sound strictly necessary. > >> > >> As for the strict variant, however, as per: > >> http://www.openmath.org/cd/set1.xhtml#suchthat > >> the base set should be mentioned indeed > >> > >> so it should be > >> > >> <apply><csymbol cd="set1">suchthat</csymbol> > >> <csymbol cd="setname1">R</csymbol> > >> <bind><csymbol cd="fns1">lambda</csymbol> > >> <bvar><ci>x</ci></bvar> > >> <apply><csymbol cd="interval1">interval</csymbol> > >> <cn>0</cn> > >> <ci>x</ci> > >> </apply> > >> </bind> > >> </apply> > >> > >> hope it helps > >> > >> paul > >> > >> Le 11-févr.-09 à 18:55, Robert Miner a écrit : > >>> I've been pressing ahead with 4.3 and got up to the examples in > >>> 4.3.1 > >>> Container Markup for Constructor Symbols. > >>> > >>> One of them is the set of all intervals (0,x). Both parts looked > >>> wrong > >>> to me. > >>> > >>> We had > >>> > >>> <set> > >>> <bvar><ci>x</ci></bvar> > >>> <interval><cn>0</cn><ci>x</ci></interval> > >>> </set> > >>> > >>> which doesn't define anything since the range of the bound variable > >>> isn't defined. I think it should be > >>> > >>> <set> > >>> <bvar><ci>x</ci></bvar> > >>> <domainofapplication><reals/></domainofapplication> > >>> <interval><cn>0</cn><ci>x</ci></interval> > >>> </set> > >>> > >>> or > >>> > >>> <set> > >>> <bvar><ci>x</ci></bvar> > >>> <condition><apply><in/><ci>x</ci><reals/></apply></condition> > >>> <interval><cn>0</cn><ci>x</ci></interval> > >>> </set> > >>> > >>> > >>> However, the real trouble comes with the strict encoding. It's > >>> currently > >>> > >>> <apply><csymbol cd="set1">suchthat</csymbol> > >>> <bind><csymbol cd="fns1">lambda</csymbol> > >>> <bvar><ci>x</ci></bvar> > >>> <apply><csymbol cd="interval1">interval</csymbol> > >>> <cn>0</cn> > >>> <ci>x</ci> > >>> </apply> > >>> </bind> > >>> </apply> > >>> > >>> But this is clearly wrong, since "suchthat" is a function taking > two > >>> arguments, a set and a Boolean valued expression on that set which > >>> determines a subset. Was there some experimental MathML 3 version > >>> of > >>> suchthat at some point? > >>> > >>> Anyway, I'm scarcely an expert, but I don't see how to do this > >> example > >>> without using something like big_union, and I don't want to get > into > >>> that at this point. Seems like a simpler example is in order. I > >>> can > >>> cook one up, but I wanted to be sure I was on solid ground first. > >>> > >>> --Robert > >>> > >>> > >>> > > > > _______________________________________________ Om3 mailing list [email protected] http://openmath.org/mailman/listinfo/om3
