Re: Question concerning MakeBoxes

*To*: mathgroup at smc.vnet.net*Subject*: [mg60420] Re: Question concerning MakeBoxes*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Fri, 16 Sep 2005 03:48:59 -0400 (EDT)*Organization*: The University of Western Australia*References*: <dg8loi$rf1$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <dg8loi$rf1$1 at smc.vnet.net>, Cca <cca at gregosetroianos.mat.br> wrote: > Let's start a new Mathematica (5.1) session and note that > > FormatValues[And] > > is the empty list. I want to define a rule for formatting logical > conjunctions and disjunctionsin in such a way that, for example, > the conjunction > > p&&q&&r > > is formatted in TraditionalForm as > > RowBox[{"\[And]", > RowBox[{StyleBox["{",SpanMaxSize->\[Infinity]], > GridBox[{{"p"},{"q"},{"r"}},ColumnAlignments->{Left}], > StyleBox["}",ShowContents->False]}]," "}]//DisplayForm Note that you can use \[AutoRightMatch] instead of hiding the right "}". > (As far as I know, the idea for this interesting and convenient "grid > notation" is due to Bruno BuchBerger, but this is another history.) Perhaps there an implementation of this notation in Theorema then? See http://www.risc.uni-linz.ac.at/people/buchberg/theorema_project.html > For me, one obvious solution to this problem should be something like > > Unprotect[And]; > And/:MakeBoxes[And[c__],TraditionalForm]:= > RowBox[{"\[And]", > RowBox[{StyleBox["{",SpanMaxSize->\[Infinity]], > GridBox[{#}&/@(MakeBoxes[#,TraditionalForm]&/@{c}), > ColumnAlignments->{Left}], > StyleBox["}",ShowContents->False]}]," "}]; > Protect[And]; > > In fact, > > p&&q&&r//TraditionalForm > > is now displayed as intended. However, it works only once: evaluating again > > p&&q&&r//TraditionalForm > > gives the built-in traditional formatting. After inspecting > > FormatValues[And] > > we see what is going on: my formatting rule is the LAST on the list. So, in > order to > force Mathematica to apply my definition first, I evaluate > > Unprotect[And]; > FormatValues[And]=Reverse@FormatValues[And]; > Protect[And]; > > This solves my problem, but in a somewhat inelegant way. > > My questions are: > > (1) what is the explanation for this behavior? > (2) how can I get the intended result without reversing FormatValues[And]? I would expect that you could use the Notation package to do what you want more directly. Cheers, Paul _______________________________________________________________________ Paul Abbott Phone: 61 8 6488 2734 School of Physics, M013 Fax: +61 8 6488 1014 The University of Western Australia (CRICOS Provider No 00126G) AUSTRALIA http://physics.uwa.edu.au/~paul