[Tex/LaTex] grabbing a single Greek glyph from an alternative font in math mode

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I have a physics textbook that is used by students who typically have no previous familiarity with the Greek alphabet. In the Computer Modern math font, lowercase gamma is highly stylized. The loop at the bottom is squashed flat so that there is no white space inside. It's perfectly legible to people who are already familiar with the Greek alphabet, but for my students it is endlessly confusing. They think it looks just like the Latin "y," and they write it that way on their homework. It drives me crazy, and I would dearly love to find a way to substitute some other font for that one character in math mode. Is there a way to do this?

Here are some similar questions on this site with answers that don't quite work for me:

Change font in a single paragraph — This one doesn't seem to do anything in math mode.

Importing a Single Symbol From a Different Font — This approach might work, but mathabx doesn't include an alternative set of Greek characters.

Replacing greek glyphs in math mode — This is about replacing the entire Greek alphabet with some other font. I don't have any problem with that, if it's a reasonable-looking font. However, the only solution that worked seemed to be unicode-math, which is for xetex and luatex; I'm using pdftex, and I'm not crazy about switching this large project to xetex or luatex.

Best Answer

You can use a modified version of Importing a single symbol from a different font

\usepackage[T3,T1]{fontenc}
\makeatletter
\newcommand\ipamathsymbol[2][\mathord]{%
  #1{\@ipamathsymbol{#2}}}
\def\@ipamathsymbol#1{\mathchoice
  {\@ipam@thsymbol{#1}\tf@size}
  {\@ipam@thsymbol{#1}\tf@size}
  {\@ipam@thsymbol{#1}\sf@size}
  {\@ipam@thsymbol{#1}\ssf@size}}
\def\@ipam@thsymbol#1#2{%
  \mbox{\fontsize{#2}{#2}\usefont{T3}{cmr}{m}{sl}\symbol{#1}}}
\makeatother
\renewcommand{\gamma}{\ipamathsymbol{71}}

Loading the T3 encoding is necessary, since the tipa fonts are available only in that encoding. Change T1 in OT1 if the latter is your default encoding. I've left the entire infrastructure rather than defining a one shot command, so one can play with other symbols as well; \ipamathsymbol has an optional argument (the math kind of the symbol, default \mathord) and the mandatory argument is the slot number of the chosen glyph.

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