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Re: Operator Dictionary MathML 2 vs. MathML 3

From: Neil Soiffer <neil.soiffer@gmail.com>
Date: Fri, 4 Sep 2009 07:42:48 -0700
Message-ID: <d98bce170909040742u63145ab6jeb48d3a73974d9ea@mail.gmail.com>
To: Max Berger <max@berger.name>
Cc: www-math@w3.org
The operator dictionary is informative, not normative, so "compatibility"
really isn't broken.  The operator dictionary had languished for many years
and we have put some effort into updating it to include many new Unicode
characters.  We made a number of fixes to the operator dictionary in early

I believe the version in MathML 3 should be considered more reliable.  In
the case of "-", the spacing has *not* changed.  In MathML 2, it was
"mediumspace" and that is what it is in the operator dictionary for MathML 3
(at least in the current working draft).  You can see the latest changes by
viewing the "editor's draft" at

I do see that we somehow lost the prefix forms to at least + and -, so that
will need to get fixed.

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

On Thu, Sep 3, 2009 at 7:10 AM, Max Berger <max@berger.name> wrote:

> Dear MathML experts,
> since the operator dictionary in MathML 3 changed from the one in MathML
> 2, which one is preferred for visual renderers? There are many small
> differences (e.g. the space around "-"), which will break compatibility
> with previous versions. As there is no indication in the MathML file
> which version is preferred, what is the recommended implementation?
> Should an implementation provide a switch for MathML 2 vs. 3 rendering
> mode?
> Rationale: JEuclid ( http://jeuclid.sourceforge.net/ ) is currently
> being prepared for MathML 3 support.
> Max
> --
> http://max.berger.name/
> OpenPGP ID: C93C5700 Fpr: AB6638CE472A499B3959 ADA2F989A2E5C93C5700
Received on Friday, 4 September 2009 14:43:36 UTC

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