Content mathml

The authoritative reference for Content MathML is Section 4 of the MathML 2.0 Specification . The World Wide Web Consortium (W3C) is the body that wrote the specification forMathML. The text is very readable and it is easy to find what you are looking for. Look there for answers to questions thatare not answered in this tutorial or when you need more elaboration. This tutorial is based on MathML 2.0.

In this document, the m prefix is used to denote tags in the MathML namespace. Thus the <apply> tag is referred to as <m:apply> . Remember all markup in the MathML namespace must be surrounded by <m:math> tags.

The fundamentals of content mathml: applying functions and operators

The fundamental concept to grasp about Content MathML is that it consists of applying a series of functions and operators toother elements. To do this, Content MathML uses prefix notation. Prefix notation is when the operator comes first and is followed by the operands. Here is how towrite "2 plus 3". <m:math> <m:apply> <m:plus/> <m:cn>2</m:cn> <m:cn>3</m:cn> </m:apply> </m:math> This would display as $2+3$ .

There are three types of elements in the Content MathML example shown above. First, there is the apply tag, which indicates that an operator (or function) is about to be applied to the operands. Second, there is the functionor operator to be applied. In this case the operator, plus , is being applied. Third, the operands follow the operator. In this case the operands are thenumbers being added. In summary, the apply tag applies the function (which could be sin or $f$ , etc.) or operator (which could be plus or minus, etc.) to the elements that follow it.

Tokens

Content MathML has three tokens: ci , cn , and csymbol . A token is basically the lowest level element. The tokens denote what kind of element you are acting on.The cn tag indicates that the content of the tag is a number. The ci tag indicates that the content of the tag is an identifier. An identifier could be any variable or function; $x$ , $y$ , and $f$ are examples of identifiers. In addition, ci elements can contain Presentation MathML. Tokens, especially ci and cn , are used profusely in Content MathML. Every number, variable, or function is marked by a token.

csymbol is a different type of token from ci and cn . It is used to create a new object whose semantics is defined externally. It cancontain plain text or Presentation MathML. If you find that you need something, such as an operator or function, that isnot defined in Content MathML, then you can use csymbol to create it.

Both ci and csymbol can use Presentation MathML to determine how an identifier or a newsymbol will be rendered. To learn more about Presentation MathML see Section 3 of the MathML 2.0 Specification . For example, to denote " $x$ with a subscript 2", where the 2 does not have a more semantic meaning, you woulduse the following code. <m:math> <m:ci> <m:msub> <m:mi>x</m:mi> <m:mn>2</m:mn> </m:msub> </m:ci> </m:math> This would display as $x_2$ .