This is the bguq font, a font which contains a single character:
the Begriffsschrift quantifier, in several sizes, used to set the
Begriffsschrift (concept notation) of Frege.
This package is not intended for end users, instead it is expected
that it will be used by other packages which implement the
Begriffsschrift. Josh Parsons' begriff package
http://www.tex.ac.uk/tex-archive/macros/latex/contrib/begriff/
or a derivative of it would be the obvious candidates. An example
of such usage can be found in the included style file begriff-bguq.sty,
which is an unofficial and modified version of Parsons' begriff.sty,
included only as an illustration of how package maintainers might
use the font.
The file begriff-bguq.sty is a derivative work of begriff.sty
(Copyright (c) 2005 J. Parsons, R. Heck) and so, like it, is
released under the GNU General Public License (version 2).
The remainder of this work is Copyright (c) 2012 J.J. Green and
subject to the LaTeX Project Public License.
J.J. Green 2012