Problem with lualatex, TeXGyre Pagella Math and mathbf
The warning appears with fontspec
version 2.7h, but disappears with version 2.7i (just downloaded).
However, you should be using \symbf{R}
.
You probably want \symbfup
or \symbfit
to get individual bold letters in math mode.
In unicode-math
, \mathbf
and \mathrm
are intended more for complete words, such as \frac{\mathrm{RISE}}{\mathrm{RUN}}
.
If you want to denote the Euclidean space ℝ², a good alternative is to use the blackboard letter \symbb{R}
or, for compatibility, \mathbb{R}
.