Reminder: MathML meeting on Thursday

 The meeting details were sent to the W3C members-only "member-math"
mailing list
<https://lists.w3.org/Archives/Member/member-math/2021May/0000.html> for
the group. The regulars for this group should have the meeting details in
their calendars.

In the last two meetings, we've made some very good progress resolving some
big picture issues. There is one more big picture issue for this week and
we'll also get into some details.

Agenda
1. Announcements/Updates/Progress reports
2. Defaults (comment thread starting here on #433
<https://github.com/w3c/mathml/issues/433#issuecomment-1420212046>)
3. What properties (and maybe intent names) should be in core?