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Point to the MathML Core spec for the actual proposals.
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‎generate-math-variant-tables.py

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This file was deleted.

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

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@@ -86,10 +86,7 @@ on this proposal see
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* OpenType math fonts have values about how the script should scale down when
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going from script level 0 to script level 1 (`scriptPercentScaleDown`) or 2
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(`scriptScriptPercentScaleDown`). Although this propopal simply uses constant
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values, in theory the evolution of font-size could depend on these
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parameters. If they are considered in the future, having actual script level
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values would help implementers.
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(`scriptScriptPercentScaleDown`).
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## Status in Web Engines
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### CSS `math-style` property
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<table>
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<tbody>
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<tr><th>Name:</th><td>'math-style'</td></tr>
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<tr><th>Value:</th><td>display | inline</td></tr>
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<tr><th>Initial:</th><td>inline</td></tr>
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<tr><th>Applies to:</th><td>All elements</td></tr>
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<tr><th>Inherited:</th><td>yes</td></tr>
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<tr><th>Percentages:</th><td>n/a</td></tr>
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<tr><th>Media:</th><td>visual</td></tr>
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<tr><th>Computed value:</th><td>specified keyword</td></tr>
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<tr><th>Canonical order:</th><td>n/a</td></tr>
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<tr><th>Animation type:</th><td>not animatable</td></tr>
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</tbody>
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</table>
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If the value of `math-style` is 'inline', the math layout on descendants
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should try to minimize the
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[logical height](https://drafts.csswg.org/css-writing-modes-4/#extent).
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This includes how `font-size` is changed when `math-script-level` is 'auto'
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as well
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miscelleanous layout rules described for the `displaystyle` attribute of MathML.
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If the value of `math-style` is 'display', the math layout should not take
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such constraints into consideration.
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See https://mathml-refresh.github.io/mathml-core/#the-math-style-property
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### CSS `math-script-level` property
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<table>
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<tbody>
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<tr><th>Name:</th><td>math-script-level'</td></tr>
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<tr><th>Value:</th><td>auto | add(&lt;integer&gt;) | &lt;integer&gt;</td></tr>
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<tr><th>Initial:</th><td>0</td></tr>
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<tr><th>Applies to:</th><td>All elements</td></tr>
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<tr><th>Inherited:</th><td>yes</td></tr>
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<tr><th>Percentages:</th><td>n/a</td></tr>
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<tr><th>Media:</th><td>visual</td></tr>
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<tr><th>Computed value:</th><td>see individual properties</td></tr>
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<tr><th>Canonical order:</th><td>n/a</td></tr>
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<tr><th>Animation type:</th><td>not animatable</td></tr>
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</tbody>
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</table>
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If the specified value of `math-script-level` is 'auto' and the inherited
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value of `math-style` is 'display' then the computed value of
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`math-script-level` is the inherited value.
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If the specified value of `math-script-level` is 'auto' and the inherited
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value of `math-style` is 'inline' then the computed value of
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`math-script-level` is the inherited value plus one.
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If the specified value of `math-script-level` is of the form
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'add(&lt;integer&gt;)' then
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the computed value of `math-script-level` is the inherited value
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plus the specified integer.
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If the specified value of `math-script-level` is of the form '&lt;integer&gt;'
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then the computed value of `math-script-level` is set to the specified integer.
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If `font-size` is specified or if the specified value of `math-script-level`
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is `initial` then `math-script-level` does not affect the computed value of
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`font-size`.
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Otherwise, the computed value of `font-size` is obtained by multiplying the
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inherited value of `font-size` by a nonzero scale factor calculated by the
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following procedure:
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1. Let A be the inherited `math-script-level`, B the computed
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`math-script-level`, C be 0.71 and S be 1.0
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* If A = B then return S.
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* If B < A, swap A and B and set `InvertScaleFactor` to true.
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* Otherwise B > A and set `InvertScaleFactor` to false.
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2. Let E be B - A > 0.
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3. If the inherited font has an OpenType MATH table:
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* Read `scriptPercentScaleDown` and fallback to C if the MathVariants table is absent or provides a null value.
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* Read `scriptScriptPercentScaleDown` and fallback to C<sup>2</sup> if the MathVariants table is absent or provides a null value.
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* If A ≤ 0 and B ≥ 2 then multiply S by `scriptScriptPercentScaleDown` and
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decrement E by 2.
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* Otherwise if A = 1 then multiply S by
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`scriptScriptPercentScaleDown` / `scriptPercentScaleDown` and
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decrement E by 1.
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* Otherwise if B = 1 then multiply S by `scriptPercentScaleDown`
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and decrement E by 1.
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4. Multiply S by C<sup>E</sup>
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5. Return S if `InvertScaleFactor` is false and 1/S otherwise.
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See https://mathml-refresh.github.io/mathml-core/#the-math-style-property
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### Native implementations of `display`, `displaystyle` and `scriptlevel`
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The proposal allows to partially implement the `display`, `displaystyle` and
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`scriptlevel` attributes as follows:
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* Map `scriptlevel="+U"` to 'math-script-level: add(U)' (where U is an [unsigned integer](https://www.w3.org/Math/draft-spec/chapter2.html#type.unsigned-integer)).
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* Map `scriptlevel="-U"` to 'math-script-level: add(-U)' (where U is an [unsigned integer](https://www.w3.org/Math/draft-spec/chapter2.html#type.unsigned-integer)).
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* Map `scriptlevel="U"` to 'math-script-level: U' (where U is an [unsigned integer](https://www.w3.org/Math/draft-spec/chapter2.html#type.unsigned-integer)).
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Then add rules equivalent to the following user agent stylesheet for MathML.
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Note that some rendering engines do not allow universal selectors in their
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user agent stylesheets and so such rules must be expanded to list all possible
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MathML elements.
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<pre>
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@namespace url(http://www.w3.org/1998/Math/MathML);
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math {
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math-style: inline;
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math-script-level: initial;
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}
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math[display="block"] {
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math-style: display;
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}
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math[display="inline"] {
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math-style: inline;
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}
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math[displaystyle="false"] {
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math-style: inline;
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}
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math[displaystyle="true"] {
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math-style: display;
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}
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mtable {
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math-style: inline;
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}
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mtable[displaystyle="true"] {
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math-style: display;
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}
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mstyle[displaystyle="false"] {
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math-style: inline;
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}
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mstyle[displaystyle="true"] {
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math-style: display;
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}
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mfrac > * {
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math-script-level: auto;
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math-style: inline;
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}
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mroot > :not(:first-child) {
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math-script-level: add(2);
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math-style: inline;
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}
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msub > :not(:first-child),
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msup > :not(:first-child),
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msubsup > :not(:first-child),
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mmultiscripts > :not(:first-child),
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munder > :not(:first-child),
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mover > :not(:first-child),
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munderover > :not(:first-child) {
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math-script-level: add(1);
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math-style: inline;
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}
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</pre>
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See https://mathml-refresh.github.io/mathml-core/#attribute-display,
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https://mathml-refresh.github.io/mathml-core/#attribute-displaystyle
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and https://mathml-refresh.github.io/mathml-core/#attribute-scriptlevel

‎math-variant-explainer.md

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### New CSS `text-transform` values
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The proposal is to extend the `text-transform` properties with new values:
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`none | [capitalize | uppercase | lowercase ] || full-width || full-size-kana | math-auto | math-bold | math-italic | math-bold-italic | math-double-struck | math-bold-fraktur | math-script | math-bold-script | math-fraktur | math-sans-serif | math-bold-sans-serif | math-sans-serif-italic | math-sans-serif-bold-italic | math-monospace | math-initial | math-tailed | math-looped | math-stretched`
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On text nodes containing a unique character, 'math-auto' has the same
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effect as 'math-italic', otherwise it has no effects.
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For all the other 'math-...' values,
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the transformed text is obtained by performing
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conversion of each character that have a mapping in the
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[math-variant tables](math-variant-tables.md) according
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to the specified `math-variant` value.
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UAs may decide to rely on italic, bold and bold-italic font-level properties
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when available fonts lack the proper glyphs to perform 'math-auto',
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'math-italic', 'math-bold', 'math-bold-italic' character-level transforms.
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See https://mathml-refresh.github.io/mathml-core/#new-text-transform-values
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### Native implementation of the `mathvariant` attribute
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The `mathvariant` attribute can be implemented natively by relying on the
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`text-transform` property. For any MathML element accepting the `mathvariant`
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attribute that has a `mathvariant` attribute with a valid value, set the CSS
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property on that element to the corresponding `text-transform` value.
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The `normal` value is mapped to 'none'.
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See https://mathml-refresh.github.io/mathml-core/#attribute-mathvariant

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