math-script-level-and-math-style-comments.md

math-script-level and math-style comments

Script level increment in munder, mover, munderover scripts

The current proposal does not handle the case when underover scripts are "accents". See issue 76.

scriptsizemultiplier and scriptminsize attributes

MathML also describes some scriptsizemultiplier and scriptminsize attributes to respectively specify another value for the scale factor S (default is 0.71, approximately one over square root of 2) and ensure script level change cannot scale down font-size lower than a minimal value. This is implemented in Gecko but that makes things very complex.

We should probably remove these attributes from MathML Core.

OpenType MATH values: scriptPercentScaleDown and scriptScriptPercentScaleDown

OpenType math fonts have values about how the script should scale down when going from script level 0 to script level 1 (scriptPercentScaleDown) or 2 (scriptScriptPercentScaleDown). That would suggest that a user-specified scriptsizemultiplier is not really want, instead the one specified by the font designer should be used.

Note that TeX or Microsoft Office ignore other script level changes, which would be equivalent to replacing 0.71 with 1 in the definition of S_p,p+1. The current definition tries to preserve MathML's special behavior.