HTML-Math Working Group Charter

Version 1.3, 1 April 1997 (Links updated 20 October 1997)

Scope

The HTML-Math working group is developing means to enable the use of mathematical formalism in Web documents. Since this is, in full generality, a very large complex of problems the group has selected a still wide-reaching set of more specific goals to work on.

Overall goals of the group

To develop an open specification for math to be used with HTML that:

Is suitable for teaching, and scientific communication;
Is easy to learn and to edit by hand for basic math notation, such as arithmetic, polynomials and rational functions, trigonometric expressions, univariate calculus, sequences and series, and simple matrices;
Is well suited to template and other math editing techniques;
Insofar as possible, allows conversion to and from other math formats, both presentational and semantic, such as TeX and computer algebra systems. Output formats may include graphical displays, speech synthesizers, computer algebra systems input, other math layout languages such as TeX, plain text displays (e.g. VT100 emulators), and print media, including braille. It is recognized that conversion to and from other notational systems or media may lose information in the process;
Allows the passing of information intended for specific renderers;
Supports efficient browsing for lengthy expressions;
Provides for extensibility, for example through contexts, macros, new rendering schemas or new symbols. Some extensions may necessitate the use of new renderers.

The above goals were ratified by the group at its meeting in October 1996

Criteria for the completion of work

The group's work will be complete when:

A formal specification of an HTML-Math markup scheme has been approved by consensus of group members. The scheme will:
- suffice as a basis for visual rendering of most mathematical notation (e.g. at the level of a research mathematics journal article); and
- enable renderings to other forms as mentioned above to a level acceptable to group members.
A sample implementation of software which visually renders mathematical notation as specified in item 1 exists that (a) demonstrates feasibility of the notation, and (b) facilitates implementation of rendering engines for other media.

The above criteria were ratified by the group at its meeting in October 1996

Relationships to other forums

Inside the W3C:

HTML Working Group

The wish for <MATH>, <MATHDISP>, <F> and <FD> tags, and for corresponding Content-Math-Type and Content-Mathdisp-Type META data entails coordination with this Working Group. The interaction of <MATH>, <MATHDISP> <F> and <FD> with the <DIV> tag is another such issue. [See for example HTML Dialects: Internet Media and SGML Document Types]

Document Object Model (DOM) Working Group

The interaction of the <MATH>, <MATHDISP> and <MATHNOTN> object contents with the surrounding contexts and their availability to such external processes as searching mean that there has to be liaison with this Working Group over the demands made by math on the API for presentation purposes. Scripting may also be a concern, as are applet lifetime issues. Overlap of membership in both Working Groups is very desirable.

Two-dimensional notational considerations similar to those encountered in mathematics may be of interest to other disciplines such as chemistry, music or theatre.

Style Sheets Working Group

Presentation of rendered mathematics will gladly use what help it can obtain from the use of style sheets to reduce the amount of explicit display markup required. The standards of this Working Group need to be employed, but HTML-Math may have explicit requirements that would be very useful for math. Aural presentations, as well as visual, are considered by this Working Group. The most important demand that math imposes on a style sheet mechanism is that the style sheet language be extensible. If this cannot be met directly then the HTML-Math WG must propose enough style attributes specific to math.

Web Accessibility Initiative

The fact that an explicitly stated goal of this Working Group has from its inception been to make more math readily available to the visually handicapped means that an aspect of our work comes within the purview of this Working Group.

Digital Signatures Initiative

The plausible use of digital signatures on documents, macro dictionaries, semantic lexica and fonts, which are all of more robust use if properly authenticated, means that the HTML-Math Working Group should keep informed of the results of this Working Group, with a view to their use for math purposes. It seems that what were interested in may be treated under the rubric DSig Common Manifest Format or DCMF.

XML Working Group

It is intended that the fundamental HTML-Math specification for fully marked up mathematical expressions be XML-compliant. Therefore liaison with this Working Group is essential.

Internationalization Working Group

Since mathematics is an international language perhaps there are consequences of this group's deliberations that will affect us.

Outside the W3C

IETF

The wish for META data such as Content-Math-Type and an associated MIME type means that an IETF proposal will have to be written and submitted. This will happen only once there is a well-documented HTML-Math specification.

WG8 of ISO 12083

This ISO Working Group is working on the problems of the SGML specification of mathematics. Cooperation should be attempted by continuing to have participants common both Working Groups, in particular concerned with the "Workitem Mathematics".

OpenMath

This body is concerned with codifying mathematics in a well-structured way with a view to the key issue:

How to convey specific mathematical objects and commands between algebra systems so that their meanings are conserved.

Cooperation is being achieved since several members are involved in both Working Groups.

Unicode Consortium

Mathematics concern with the visual forms of its symbols means that we shall be concerned both with the characters and glyphs we use. It will be desirable to request from Unicode the registration of a large number of characters used in mathematics but as yet with no place in Unicode.

AFII

The Association for Font Information Interchange operators a registry for glyphs in fonts. In our quest for compliance with international standards, where possible we need to be clear on what this group mandates for our symbol descriptions.

ISO TR9573:13 Working Group

This group is setting out a new recommendation for SGML entity names which includes many of those used in math. There will be a revision of the entity listing part of TR9573, and this will presumably be used by the revised form of ISO 12083, of which the math fragment has served as a basis for many of the HTML-Math Working Group's discussions. ISO TC 145, Graphical Symbols, explicitly excludes the consideration of those of interest to math. At the moment, the public entity sets given as mere examples in the informative annexes of ISO 8879:1986 (this is an ISO standard) act as de-facto standard.

Other groups or projects concerned with math encoding

These efforts include the Multi Protocol, the Central Control system with the ASAP protocol, Mathematica's MathLink protocol, MathBus interchange format (part of the Collaborative Mathematics Environments project at Cornell), and others. The number of these attempts to capture something of mathematics for interchange or programming purposes merely indicates the real extent to which this specialized notation continues to pose problems.

Deliverables and Dates

The final deliverables are generally specified in the criteria for completeness. We expect to operate in two phases with preliminary specification and sample implementation completed by May 15, 1997 and a final phase to be completed a year later.

The above paragraph is taken from the October 1996 draft

As of March 1997 we may see the following sequence of tasks, results, and goal dates:

Initial prototype
- An agreed specification of a core XML-compliant standard for a markup covering math roughly as far as college. (May 15, 1997)
  Extensions protocols to make input more user-friendly and customizable will follow later, and be part of the final HTML-Math recommendations of this Working Group.
- A prototype Java implementation using this standard for math expression markup. The implementation will also accept an experimental input format some find more natural than the full HTML-Math standard's markup. It will effect display on browser pages using whatever work-arounds prove necessary to cope with the lack of a good API for applets within browser pages. (May 15, 1997)
Character and entity conventions
- A correspondence between characters used by mathematics but not in common textual use and a chosen set of entity names, based where possible on those already assigned by previous influential methods of computer composition of mathematics. (July 1, 1997, in good time to be represented as our opinion on entity names to the TR9573 Working Group)
- A list of suggested sources of fonts to permit printed and visual representations of as many HTML-Math entities as possible. (July 1, 1997)
- A first proposal to Unicode of characters which need to be added to their tables for math purposes. (July 1, 1997)
Final prototypes (May 15, 1998)
- An agreed specification of an HTML-Math standard now covering math research papers and showing extensibility mechanisms.
- At least one full implementation using this standard for math expression markup, demonstrating the characteristics set out in our overall goals.
- Report on audio rendering of HTML-Math expressions.
- Demonstration of transfer of HTML-Math expressions to and from some computer algebra system.
- A second proposal of Unicode additions.
- Submission of a document to the IETF for the purpose of registering a MIME type.

Membership Criteria

Membership in the HTML-Math Working Group is available (a) to nominees of W3C Member organizations who indicate their involvement with encoding of mathematics and submit position papers on their views of how mathematical notation should be encoded for use within HTML documents; and (b) to invitees of the Group. All members are expected to contribute to the Group's efforts. Lack of presence for an extended period (3 months) may entail loss of Group membership.

Duration of the Working Group

As alluded to above, this Working Group's efforts in the service of mathematics on the Web are expected to finish by June 1998. Toward the end of its lifetime an assessment will be made of what further requirements there may be for better support of math on the Web.

Meetings and Work Style

The Working Group gathers for face-to-face discussions at least once every 6 months. Regular weekly teleconference meetings will be held otherwise throughout its lifetime. It is expected that members participate in these teleconferences regularly at least some of the time, but that otherwise they contribute to the Working Group's success by undertaking some of the many subsidiary tasks that are necessary, according to their expertises and as their other commitments permit. Different subcommittees will often have to work together to produce some results to feed into the whole process.

Openness Policies

In the interests of both the openness required to gain feedback from the community to inform the Working group in its work, and of publicity for its proposals for handling Web math, the Working Group shall maintain Web pages at the W3C showing its Charter, chosen documents and proposals written by its members during the course of deliberations, information about its ongoing activities, and other items of interest to those concerned with the presentation and exchange of math on the Web.

To ensure the freedom of discussion sometimes necessary for an open and fruitful exchange of views the e-mail archives of the Working Group will not be open to other than group members.

Resources Required

Within W3C
1. Support with planning and logistics for meetings for face-to-face discussion probably held at roughly 6-month intervals. This will involve obtaining meeting space, reserving accommodation for participants and catering so as to maximize effective working time.
2. Web pages at the W3C site to post the information referred to under Openness above.
3. Use of teleconferencing facilities for a regular weekly hour-long telephone discussion meeting.
4. A contact person at the W3C to coordinate the above, to keep a watching brief on the running of the Working Group, and to make arrangements when results are to be put before the W3C.
Outside W3C
Aside from the dedicated work of the Group members, a chair is required to facilitate discussion and coordinate efforts; the tasks of posting minutes and other materials to the groups Web pages must be taken care of too. Patrick Ion and Robert Miner have volunteered to serve the Group by performing these roles as joint Co-Chairs from 12 March 1997.

Send comments to Patrick Ion (ion@math.ams.org) or to Robert Miner (rminer@geom.umn.edu)