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Re: [MathML3-last-call] Clarify how "symmetric" should be set by the Operator Dictionary

From: Neil Soiffer <neil.soiffer@gmail.com>
Date: Wed, 7 Oct 2009 09:35:38 -0700
Message-ID: <d98bce170910070935l384915dbs832ea73d164178e1@mail.gmail.com>
To: Frédéric WANG <fred.wang@free.fr>
Cc: "www-math@w3.org" <www-math@w3.org>
Partially resolved.  The default for symmetric has been changed from "true"
to "false"

/w3ccvs/WWW/Math/Group/spec/xml/presentation-markup.xml
new revision: 1.280

The operator dictionary (Appendix C) still needs updating so that more
fences are identified and given the "symmetric='true'" setting.  Related to
this correction, more arrows should also be identified and marked as
stretchy by default.

Neil Soiffer
Senior Scientist
Design Science, Inc.
www.dessci.com
~ Makers of MathType, MathFlow, MathPlayer, MathDaisy, WebEQ, Equation
Editor ~


2009/9/29 Neil Soiffer <neil.soiffer@gmail.com>

> Thanks for spotting that.  Upon discussing this, some WG members felt that
> the default should be symmetric='true' for when someone says to stretch
> something.  That's true for fences, but for arrows, the main use case is in
> a mtable and there they should not stretch symmetrically.
>
> The tentative conclusion was that  we should remove the sentence in 3.2.5
> and do a better job of finding fences in Unicode and defaulting them to
> symmetric in Appendix C (even though very few fonts will be able to stretch
> many of them).  That gets the right behavior and allows us to continue to
> have a compact form for the table in Appendix C.
>
> While modifying Appendix C, we will try to list more of the arrows as being
> stretchy (even though most fonts don't support stretching them easily).
>
> Does anyone object to this approach?
>
> Neil Soiffer
> Senior Scientist
> Design Science, Inc.
> www.dessci.com
> ~ Makers of MathType, MathFlow, MathPlayer, MathDaisy, WebEQ, Equation
> Editor ~
>
>
>
>
> 2009/9/28 Frédéric WANG <fred.wang@free.fr>
>
> I like the compact form to list boolean valued properties of an operator in
>> Appendix C. However, in the section that describes the format of operator
>> dictionary entries, these rules are given in order to set their values:
>>
>> "Boolean valued attributes such as stretchy are specified together in the
>> final Properties column by listing the attribute name if its value should be
>> set to true by the dictionary."
>>
>> and "Any attribute not listed for some entry has its default value, which
>> is given in parentheses in the table of attributes in Section 3.2.5
>> Operator, Fence, Separator or Accent <mo>."
>>
>> If I read this correctly, the "symmetric" property should be set to "true"
>> when it is present and to its default value when it is not. But its default
>> value is still "true" according to section 3.2.5.2.1 !
>>
>>
>
Received on Wednesday, 7 October 2009 16:36:19 GMT

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