Module: Math

Any raster representation of Math shall be contained within a Formula tag and specified using MathML as described below.
All mathematical expressions shall be enclosed within a <formula> tag.
All mathematical expressions that can be represented by MathML may be represented as MathML using a <math> tag inside a <formula> tag.
All nonlinear mathematical expressions that can be represented by MathML shall be represented by MathML.
The Text Module's requirement's regarding mapping of characters to Unicode apply to math. This means that any character that can be represented by a Unicode character should use a Unicode code point. For those characters that do not have a Unicode mapping, replacement text as specified in PDF Reference 1.7 10.8.3 "Replacement Text", pg. 944 (ISO 32000: 14.9.4 Replacement Text, pg. 611) shall be used. In particular, this requirement applies to stretchable characters (braces, brackets, integrals, ...) which are often drawn by putting together several glyphs; such characters shall be tagged using Actual Text.

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