Mathematical Markup Language (MathML) Version 3.0

W3C Working Draft 04 June 2009

This version:
Latest MathML 3 version:
Latest MathML Recommendation:
Previous version:
David Carlisle, NAG
Patrick Ion, Mathematical Reviews, American Mathematical Society
Robert Miner, Design Science, Inc.
Principal Authors:
Ron Ausbrooks, Stephen Buswell, David Carlisle, Giorgi Chavchanidze, Stéphane Dalmas, Stan Devitt, Angel Diaz, Sam Dooley, Roger Hunter, Patrick Ion, Michael Kohlhase, Azzeddine Lazrek, Paul Libbrecht, Bruce Miller, Robert Miner, Murray Sargent, Bruce Smith, Neil Soiffer, Robert Sutor, Stephen Watt

In addition to the HTML version, this document is also available in these non-normative formats: XHTML+MathML version and PDF version.


This specification defines the Mathematical Markup Language, or MathML. MathML is an XML application for describing mathematical notation and capturing both its structure and content. The goal of MathML is to enable mathematics to be served, received, and processed on the World Wide Web, just as HTML has enabled this functionality for text.

This specification of the markup language MathML is intended primarily for a readership consisting of those who will be developing or implementing renderers or editors using it, or software that will communicate using MathML as a protocol for input or output. It is not a User's Guide but rather a reference document.

MathML can be used to encode both mathematical notation and mathematical content. About thirty-eight of the MathML tags describe abstract notational structures, while another about one hundred and seventy provide a way of unambiguously specifying the intended meaning of an expression. Additional chapters discuss how the MathML content and presentation elements interact, and how MathML renderers might be implemented and should interact with browsers. Finally, this document addresses the issue of special characters used for mathematics, their handling in MathML, their presence in Unicode, and their relation to fonts.

While MathML is human-readable, in all but the simplest cases, authors use equation editors, conversion programs, and other specialized software tools to generate MathML. Several versions of such MathML tools exist, and more, both freely available software and commercial products, are under development.

Status of this Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This document is a W3C Public Working Draft produced by the W3C Math Working Group as part of the W3C Math Activity. The goals of the W3C Math Working Group are discussed in the W3C Math WG Charter (revised July 2006). A list of participants in the W3C Math Working Group is available.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This sixth Public Working Draft specifies a new version of the the Mathematical Markup Language, MathML 3.0 which is at present under active development. The Math WG hopes this draft will permit informed feedback. There is a description of some considerations underlying this work in the W3C Math WG's public Roadmap [roadmap]. Feedback should be sent to the Public W3C Math mailing list .

The MathML 2.0 (Second Edition) specification has been a W3C Recommendation since 2001. After its recommendation, a W3C Math Interest Group collected reports of experience with the deployment of MathML and identified issues with MathML that might be ameliorated. The rechartering of a Math Working Group allows the revision to MathML 3.0 in the light of that experience, of other comments on the markup language, and of recent changes in specifications of the W3C and in the technological context. MathML 3.0 does not signal any change in the overall design of MathML. The major additions in MathML 3 are support for bidirectional layout, better linebreaking and explicit positioning, elementary math notations, and a new strict content MathML vocabulary with well-defined semantics generated from formal content dictionaries. The MathML 3 Specification has also been restructured.

Public discussion of MathML and issues of support through the W3C for mathematics on the Web takes place on the public mailing list of the Math Working Group (list archives). To subscribe send an email to www-math-request@w3.org with the word subscribe in the subject line.

Please report errors in this document to www-math@w3.org.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

The basic chapter structure of this document is based on the earlier MathML 2.0 Recommendation [MathML2]. That MathML 2.0 itself was a revision of the earlier W3C Recommendation MathML 1.01 [MathML1]; MathML 3.0 is a revision of the W3C Recommendation MathML 2.0. It differs from it in that all previous chapters have been updated, some new elements and attributes added and some deprecated. This Public Working Draft differs in structure from the initial Public Working Draft as renewed efforts to separate the formal from the explanatory have resulted in eight chapters not seven. Much has been moved to separate documents containing Primer material, material on Characters and Entities and on the MathML DOM. First Working Drafts of these documents will be published soon. A current list of open issues, pointing into the relevant places in the draft, follows the Table of Contents.

The present draft is an incremental one making public some of the results of Math Working Group work in recent months. The biggest difference this time is in Chapter 4, although there have been smaller ameliorations throughout the specification. A more detailed description of changes from the previous Recommendation follows.

Table of Contents

1 Introduction
    1.1 Mathematics and its Notation
    1.2 Origins and Goals
        1.2.1 Design Goals of MathML
    1.3 Overview
    1.4 A First Example
2 MathML Fundamentals
    2.1 MathML Syntax and Grammar
        2.1.1 General Considerations
        2.1.2 MathML and Namespaces
        2.1.3 Children versus Arguments
        2.1.4 MathML and Rendering
        2.1.5 MathML Attribute Values
        2.1.6 Attributes Shared by all MathML Elements
        2.1.7 Collapsing Whitespace in Input
    2.2 The Top-Level math Element
        2.2.1 Attributes
        2.2.2 Deprecated Attributes
    2.3 Conformance
        2.3.1 MathML Conformance
        2.3.2 Handling of Errors
        2.3.3 Attributes for unspecified data
3 Presentation Markup
    3.1 Introduction
        3.1.1 What Presentation Elements Represent
        3.1.2 Terminology Used In This Chapter
        3.1.3 Required Arguments
        3.1.4 Elements with Special Behaviors
        3.1.5 Directionality
        3.1.6 Displaystyle and Scriptlevel
        3.1.7 Linebreaking of Expressions
        3.1.8 Warning about fine-tuning of presentation
        3.1.9 Summary of Presentation Elements
    3.2 Token Elements
        3.2.1 MathML characters in token elements
        3.2.2 Mathematics style attributes common to token elements
        3.2.3 Identifier <mi>
        3.2.4 Number <mn>
        3.2.5 Operator, Fence, Separator or Accent <mo>
        3.2.6 Text <mtext>
        3.2.7 Space <mspace/>
        3.2.8 String Literal <ms>
        3.2.9 <mglyph/>
    3.3 General Layout Schemata
        3.3.1 Horizontally Group Sub-Expressions <mrow>
        3.3.2 Fractions <mfrac>
        3.3.3 Radicals <msqrt>, <mroot>
        3.3.4 Style Change <mstyle>
        3.3.5 Error Message <merror>
        3.3.6 Adjust Space Around Content <mpadded>
        3.3.7 Making Sub-Expressions Invisible <mphantom>
        3.3.8 Expression Inside Pair of Fences <mfenced>
        3.3.9 Enclose Expression Inside Notation <menclose>
    3.4 Script and Limit Schemata
        3.4.1 Subscript <msub>
        3.4.2 Superscript <msup>
        3.4.3 Subscript-superscript Pair <msubsup>
        3.4.4 Underscript <munder>
        3.4.5 Overscript <mover>
        3.4.6 Underscript-overscript Pair <munderover>
        3.4.7 Prescripts and Tensor Indices <mmultiscripts>
    3.5 Tabular Math
        3.5.1 Table or Matrix <mtable>
        3.5.2 Row in Table or Matrix <mtr>
        3.5.3 Labeled Row in Table or Matrix <mlabeledtr>
        3.5.4 Entry in Table or Matrix <mtd>
        3.5.5 Alignment Markers <maligngroup>, <malignmark>
    3.6 Elementary Math
        3.6.1 Stacks of Characters <mstack>
        3.6.2 Long Division <mlongdiv>
        3.6.3 Group Rows with Similiar Positions <msgroup>
        3.6.4 Rows in Elementary Math <msrow>
        3.6.5 Carries, Borrows, and Crossouts <mscarries>
        3.6.6 A Single Carry <mscarry>
        3.6.7 Horizontal Line <msline/>
        3.6.8 Elementary Math Examples
    3.7 Enlivening Expressions
        3.7.1 Bind Action to Sub-Expression <maction>
    3.8 Semantics and Presentation
4 Content Markup
    4.1 Introduction
        4.1.1 The Intent of Content Markup
        4.1.2 The Structure and Scope of Content MathML Expressions
        4.1.3 Strict Content MathML
        4.1.4 Content Dictionaries
    4.2 Content MathML Elements Encoding Expression Structure
        4.2.1 Numbers <cn>
        4.2.2 Content Identifiers <ci>
        4.2.3 Content Symbols <csymbol>
        4.2.4 String Literals <cs>
        4.2.5 Function Application <apply>
        4.2.6 Bindings and Bound Variables <bind> and <bvar>
        4.2.7 Structure Sharing <share>
        4.2.8 Attribution via semantics
        4.2.9 Error Markup <cerror>
        4.2.10 Encoded Bytes <cbytes>
    4.3 Content MathML for Specific Structures
        4.3.1 Container Markup
        4.3.2 Bindings with <apply>
        4.3.3 Qualifiers
        4.3.4 Operator Classes
    4.4 Content MathML for Specific Operators and Constants
        4.4.1 Functions and Inverses
        4.4.2 Arithmetic, Algebra and Logic
        4.4.3 Relations
        4.4.4 Calculus and Vector Calculus
        4.4.5 Theory of Sets
        4.4.6 Sequences and Series
        4.4.7 Elementary classical functions
        4.4.8 Statistics
        4.4.9 Linear Algebra
        4.4.10 Constant and Symbol Elements
    4.5 Deprecated Content Elements
        4.5.1 Declare <declare>
    4.6 The Strict Content MathML Translation
5 Mixing Markup Languages
    5.1 Semantic Annotations
        5.1.1 Annotation elements
        5.1.2 Annotation references
        5.1.3 Alternate representations
        5.1.4 Flattening semantic annotations
    5.2 Elements for Semantic Annotations
        5.2.1 The semantics element
        5.2.2 The annotation element
        5.2.3 The annotation-xml element
    5.3 Combining Presentation and Content Markup
        5.3.1 Presentation Markup in Content Markup
        5.3.2 Content Markup in Presentation Markup
    5.4 Parallel Markup
        5.4.1 Top-level Parallel Markup
        5.4.2 Parallel Markup via Cross-References
6 Interactions of MathML with the Host Environment
    6.1 Introduction
    6.2 Invoking MathML Processors: namespace, extensions, and mime-types
        6.2.1 Recognizing MathML in an XML Model
        6.2.2 Resource Types for MathML Documents
        6.2.3 Names of MathML Encodings
    6.3 Transferring MathML
        6.3.1 Basic Transfer Flavors' Names and Contents
        6.3.2 Recommended Behaviors when Transferring
        6.3.3 Discussion
        6.3.4 Examples
    6.4 Combining MathML and Other Formats
        6.4.1 Mixing MathML and HTML
        6.4.2 Linking
        6.4.3 MathML and Graphical Markup
    6.5 Using CSS with MathML
        6.5.1 Order of processing attributes versus style sheets
7 Characters, Entities and Fonts
    7.1 Introduction
    7.2 Unicode Character Data
    7.3 Entity Declarations
    7.4 Special Characters Not in Unicode
    7.5 Mathematical Alphanumeric Symbols
    7.6 Non-Marking Characters


A Parsing MathML
    A.1 Use of MathML as Well-Formed XML
    A.2 Using the RelaxNG Schema for MathML3
        A.2.1 Full MathML
        A.2.2 The Grammar for Presentation MathML
        A.2.3 The Grammar for Strict Content MathML3
        A.2.4 The Grammar for Pragmatic MathML
        A.2.5 Deprecated Features
        A.2.6 MathML as a module in a RelaxNG Schema
    A.3 Using the MathML DTD
        A.3.1 Document Validation Issues
        A.3.2 Attribute values in the MathML DTD
    A.4 Using the MathML XML Schema
B Media Types Registrations
    B.1 Media type for Generic MathML
    B.2 Media type for Presentation MathML
    B.3 Media type for Content MathML
C Operator Dictionary (Non-Normative)
    C.1 Indexing of the operator dictionary
    C.2 Format of operator dictionary entries
    C.3 Notes on lspace and rspace attributes
    C.4 Operator dictionary entries
D Glossary (Non-Normative)
E Working Group Membership and Acknowledgments (Non-Normative)
    E.1 The Math Working Group Membership
    E.2 Acknowledgments
F Changes (Non-Normative)
    F.1 Changes between MathML 2.0 Second Edition and MathML 3.0
G References (Non-Normative)
H Index (Non-Normative)
    H.1 MathML Elements
    H.2 MathML Attributes

Open Issues

The following is a list of open issues which are highlighted in this draft. The issue name links to the text of the issue in this specification. There is also a W3C member-only link to the Math Working Group wiki. (Note that in many cases the wiki does not have a page discussing the issue, but will offer to create such pages on demand.) In some cases there is also a (member only) link to the Math Working Group's Issue tracking system.

Presentation Markup

mpadded-examples   wiki (member only)
mpadded examples

Interactions of MathML with the Host Environment

mime-types-for-p-and-c   wiki (member only)
Different media-types for presentation and content?
update_interface   wiki (member only)
Update Interface

Parsing MathML

update_schema   wiki (member only)
DTD and W3C XML Schema
permissive_units   wiki (member only)
more permissive lengths/widths
ednote_rnc_browserinterface_   wiki (member only)
ednote_rnc_units-patterns_   wiki (member only)
ednote_rnc_mathvariant_   wiki (member only)
ednote_mglyph_alt_   wiki (member only)
ednote_rnc_leftover-max_   wiki (member only)
ednote_rnc_opel-content_   wiki (member only)
ednote_rnc_cn-content_   wiki (member only)