Up: Table of Contents | Working Draft 6-Jan-98 |

A child of a layout schema. That is, "A is an argument of B" means "A is a child of B and B is a layout schema". Thus, token elements have no arguments, even if they have children (which can only be <malignmark/>).

**Attribute**

A parameter to (property of) an SGML or XML element (specified in
the start tag) that is composed of an attribute name and a
value.

**Axis**

The axis is an imaginary alignment line upon which a fraction line
is centered. Often, characters that can stretch such as
parenthesis, brackets, braces, summation signs, etc., and operators
are centered on the axis and are symmetric with respect to it.

**Baseline**

The baseline is an imaginary alignment line upon which a glyph
rests. The baseline is an intrinsic property of the glyph (namely a
horizontal line). Often baselines are aligned (joined) during
typesetting.

**Black box**

The bounding box of the actual size taken up by the viewable
portion (ink) of a glyph or expression.

**Block level tag**

A term used for categorizing display style (math in between
paragraphs) MathML elements.

**Cascading Style Sheets (CSS)**

A mechanism that allows authors and readers to attach style (e.g.
fonts, colors and spacing) to HTML documents.

**Character**

A member of a set of identifiers used for the organization, control
or representation of text.

**Character Data (CDATA)**

A SGML data type for raw data which does not include markup or
entity references.

**Character or expression depth**

Distance between the baseline and bottom edge of the character
glyph or expression. Also known as the descent.

**Character or expression height**

Distance between the baseline and top edge of the character glyph
or expression. Also know as the ascent.

**Character level tag**

A term used for categorizing inline (math as part of a paragraph)
MathML elements.

**Character or expression width**

Horizontal distance taken by the character glyph as indicated in
the font metrics, or the total width of an expression.

**Contained (element A is contained in element B)
**A is part of B's content.

**Content elements**

MathML elements which explicitly specify the meaning of a portion
of a MathML expression (defined in Chapter 4 of the

MathML standard).

**Context (of a given MathML expression)**

Information provided during the rendering of some MathML data to
the rendering process for the given MathML expression; especially
information about the MathML which surrounds that expression.

**Depth**

The distance from the baseline of the box to the bottom edge of the
box.

**Direct subexpression (of a MathML expression "E")
**A subexpression which is directly contained in E.

**Directly contained (element A in element B)**

A is a child of B (as defined in XML); i.e. A is contained in B,
but not in any element which is itself contained in B.

**Document Object Model** **Working Group (
DOM )**

A model in which the document or Web page is treated as an object
repository. This model is developed by the DOM

working group of the W3C.

**Document Style Semantics and Specification Language** (
DSSSL)

A method of specify the formatting and transformation of SGML
documents. ISO International Standard 10179:1996.

**Document Type Definition (DTD)**

In SGML or XML a formal definition of the elements and the
relationship among the data elements (the structure) for a
particular type of document.

**Height**

The distance from the baseline of the box to the top edge of the
box.

**Inferred <mrow>**

An <mrow> element which is "inferred" around the contents of
certain layout schema when they have other than exactly one
argument. Defined precisely in Section 3.1.5.

**Embedded object**

Objects such as Java applets, Microsoft Component Object Model
(COM) objects (e.g. ActiveX Controls and ActiveX Document
embeddings), and plug-ins which reside in an HTML document.

**Embellished operator**

An operator, including any "embellishment" it may have, such as
superscripts or style information. The "embellishment" is
represented by layout schema which contain the operator itself.
Defined precisely in Section 3.2.4.

**Entity reference**

A sequence of ASCII characters of the form &*name*; which
represents some other data, typically a non-ASCII character, a
sequence of characters, or an external source of data, eg. a file
containing a set of standard entity definitions such as
ISOLat1.

**Extensible Markup Language (XML)**

A simple dialect of SGML intended to enable generic SGML to be
served, received, and processed on the Web.

**Fences**

In typesetting, bracketing tokens like parentheses, braces, and
brackets which usually appear in matched pairs.

**Font**

A particular collection of glyphs of a typeface of a given size,
weight and style, eg "Times Roman Bold 12 point" (see the
comp.fontsFAQ).

**Glyph**

The actual shape (bit pattern, outline) of a character image.

**Input syntax layer**

A planned MathML extension mechanism designed to facilitate hand
entry of MathML content.

**Indirectly contained**

A is contained in B, but not directly contained in B.

**Instance of MathML**

A single instance of the toplevel element of MathML, and/or a
single instance of embedded MathML in some other

data format.

**Layout schema (plural: schemata)**

A presentation element defined in Sections 3.3 - 3.6, other than
the empty elements defined there (i.e. not the elements defined in
3.5.4 (about alignment) or the empty elements [none/] and
[mprescripts/] defined in 3.4.7 (about <mmultiscripts>)). The
layout schemata are never empty elements (though their content may
contain nothing in some cases), are always expressions, and all
allow any MathML expressions as arguments (except for argument
count requirements and the requirement for a certain empty element
in

<mmultiscripts>).

**Mathematical Markup Language (MathML)**

The markup language (specified in this document) for describing
mathematical expression structure, together with a mathematical
context.

**MathML element**

An XML element which describes part of the logical structure of a
MathML document

**MathML expression (within some well-formed MathML data)
**A single instance of a presentation element, except for the
empty elements <none/> or <mprescripts/> or an instance
of <malignmark/> within a token element (defined below); or a
single instance of certain of the content elements (see Section 4
for a precise definition of which ones).

**Multi-purpose Internet Mail Extensions (MIME)**

A set of specifications that offers a way to interchange text in
languages with different character sets, and multi-media content
among many different computer systems that use Internet mail
standards.

**Operator -- an <mo> element**

Used to represent ordinary operators, fences, separators in MathML
presentation. (<mo>, a token element, is defined in Section
3.2.4.)

**OpenMath**

A general representation language for communicating mathematical
objects between application programs.

**Parser Character Data (PCDATA)**

A SGML data type for raw data occurring in a context in which
entity references may occur.

**Presentation elements**

MathML tags and entities intended to express the syntactic
structure of math notation (defined in Chapter 3 of the MathML
standard).

**Presentation layout schema**

A presentation element that can have other MathML elements as
content.

**Presentation tokens elements**

A presentation element that can have only parsed character data as
content.

**Rendering**

**Selected subexpression (of an <maction>
element)**

The argument of an <maction> element (a layout schema defined
in Section 3.6) which is (at any given time) "selected" within the
viewing state of a MathML renderer, or by the **selection**
attribute when the element exists only in MathML data. Defined
precisely in Section 3.6.

**Spacelike (MathML expression)**

A MathML expression which is ignored by the suggested rendering
rules for MathML presentation elements when they determine operator
forms and effective operator rendering attributes based on operator
positions in <mrow> elements. Defined precisely in Section
3.2.6.

**Standard Generalized Markup Language (SGML)**

An ISO standard (ISO 8879:1986) which provides a formal mechanism
for the definition of document structure via DTDs ((Document Type
Definitions), and a notation for the markup of document instances
conforming to a DTD.

**Subexpression (of a MathML expression "E")**

A MathML expression contained (directly or indirectly) in E's
content.

**Suggested rendering rules for MathML presentation
elements**

Defined throughout Chapter 3; the ones which use other terms
defined here occur mainly in Section 3.2.4, but also in 3.6 and
perhaps elsewhere.

**TeX**

A software system written by Donald Knuth for typesetting
documents.

**Token element**

One of the presentation elements defined in Section 3.2
[<mi>, etc] or Section 3.5.4 [alignment elements, which are
empty], other than an empty element which (in a particular
instance) occurs inside a token element. All token elements are
either empty, or allow only PCDATA and/or <malignmark/> as
content. All token elements are MathML expressions. Not all empty
presentation elements are token elements.

**Toplevel element (of MathML)
**<math> (defined in Chapter 7)

**Typeface**

A typeface is a specific design of a set of letters, numbers and
symbols, such as "Times Roman" or "Chicago".

**Well-Formed MathML data
**MathML data which (1) conforms to the MathML DTD; (2) obeys the
additional rules defined in the MathML standard for the legal
contents and attribute values of each MathML element.

**Width**

The distance from the left edge of the box to the right edge of the
box.

Up: Table of Contents