"Mind the Gap!"  as they say on The Tube in London (the UK one).

Sent from my iPud (\~/)

On 21 May 2014, at 02:16, William F Hammond <[log in to unmask]> wrote:

On Tue, May 20, 2014 at 2:31 AM, David Carlisle <[log in to unmask]> wrote:
For that use I'd think
a variant declaration which would define \mathbf to flip the mathcodes into the U+1Dxxx block
using the base font rather than define it as a swutch to new \fam (\mathgroup)  and  would be useful.

So long as one minds the gaps in U+1Dxxx (actually the several gaps for which the unicode folk seem to have thought the characters were previously defined in the U+21xx block), though maybe it's not that much of an issue for \mathbf itself as opposed to \mathcal, \mathfrak, and \mathbb.

At least they were thoughtful enough to leave those slots empty.  :-)

Just seizing the opportunity to make everyone aware of the gaps.

        -- Bill