RE: [EXTERNAL] action item for you

Microsoft Office apps have the LaTeX concept of an equation array for displaying aligned equations such as
[cid:image003.png@01D88C68.B58D66A0]

The UnicodeMath for this equation array is

█(10𝑥+&3&𝑦=2@3&𝑥+&13&𝑦=4)

With no alignment marks, these equations in plain text are

10𝑥 + 3𝑦 = 2
3𝑥 + 13𝑦 = 4

The MathML (without prefixes) is

<math display="block">
   <mtable>
      <mtd>
         <maligngroup/>
         <mn>10</mn>
         <malignmark/>
         <mi>x</mi>
         <mo>+</mo>
         <maligngroup/>
         <mn>3</mn>
         <malignmark/>
         <mi>y</mi>
         <mo>=</mo>
         <mn>2</mn></mtd>
      <mtd>
         <maligngroup/>
         <mn>3</mn>
         <malignmark/>
         <mi>x</mi>
         <mo>+</mo>
         <maligngroup/>
         <mn>13</mn>
         <malignmark/>
         <mi>y</mi>
         <mo>=</mo>
         <mn>4</mn></mtd></mtable></math>

So the only way that <malignmark> and <maligngroup> are used is to alternate between “align” and “spacer”. The MathML 3.0 spec has additional functionality, but the Office apps don’t use it.
OfficeMath also has the “math paragraph”, which is more flexible in that it handles manual and automatic equation line breaking.

Thanks,
Murray

From: Neil Soiffer <soiffer@alum.mit.edu>
Sent: Tuesday, June 28, 2022 8:40 PM
To: Murray Sargent <murrays@exchange.microsoft.com>
Subject: [EXTERNAL] action item for you

Murray,

I forgot to put it in the agenda, but an action from last time was for you to check how much of MathML<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fw3c.github.io%2Fmathml%2Fspec.html%23presm_malign&data=05%7C01%7Cmurrays%40exchange.microsoft.com%7C0a6cd85dc51a43b5f71e08da598114f9%7C72f988bf86f141af91ab2d7cd011db47%7C0%7C0%7C637920708905006177%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000%7C%7C%7C&sdata=wjjSXAjLyANcWlWXeLiOteAbU3jbTPdZ3QUQcvW4JOw%3D&reserved=0> alignment <https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fw3c.github.io%2Fmathml%2Fspec.html%23presm_malign&data=05%7C01%7Cmurrays%40exchange.microsoft.com%7C0a6cd85dc51a43b5f71e08da598114f9%7C72f988bf86f141af91ab2d7cd011db47%7C0%7C0%7C637920708905006177%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000%7C%7C%7C&sdata=wjjSXAjLyANcWlWXeLiOteAbU3jbTPdZ3QUQcvW4JOw%3D&reserved=0> Office supports. I hope you get a chance to check this and report to the group.

Thanks,

    Neil