# Changing math font in plain TeX

I was trying to change the math font used in plain TeX (as opposed to LaTeX or ConTeXt), but I didn't seem to find it documented any where, apparently it is so obvious for TeXperts to be even documented. Anyway, I figured it out and I'm documenting it here so I don't have to search it again.

Set font families 0-3 to the new font, as follows:
0: math text ("sin", "cos", numbers, etc.)
1: math italic ("x", "y", "z", etc. don't have to be italic at all e.g. Euler)
2: math symbols
3: math extensions
\textfont: normal size font
\scriptfont: font for sub/super script
\scriptscriptfont: font for subsub/supersuper script

Something like:
``` \textfont0 = \mathtext \scriptfont0 = \mathsubtext \scriptscriptfont0 = \mathsubsubtext \textfont1 = \mathlet \scriptfont1 = \mathsublet \scriptscriptfont1 = \mathsubsublet \textfont2 = \mathsym \scriptfont2 = \mathsubsym \scriptscriptfont2 = \mathsubsubsym \textfont3 = \mathext \scriptfont3 = \mathsubext \scriptscriptfont3 = \mathsubsubext ```

## علِّق

كابتشا
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