The MathML element is used to group sub-expressions, which usually contain one or more operators with their respective operands (such as and ). This element renders as a horizontal row containing its arguments.

When writing a MathML expression, you should group elements within an in the same way as they are grouped in the mathematical interpretation of the expression. Proper grouping helps the rendering of the expression in several ways:

• It can improve the display by possibly affecting spacing and preventing line breaks.
• It simplifies the interpretation of the expression by automated systems such as computer algebra systems and audio renderers.