> Aditya Mahajan:
> By default, in all three formats the font for \log is mathupright rather
> than textrm. There needs to be a rationale for ConTeXt default to be
> different from other formats. Do you have any reference to a math book or
> journal that uses text fonts for \log-like operators?
Thanks for the examples. I had forgotten that math fonts can differ from text fonts. Now I understand why you use \mathupright (which, according to the source code is identical in math mode to \mathrm and \rm). And I know that math fonts have different kerning and ligatures than text fonts.
But how is that in LaTeX, kerning and ligatures in math mode inside \mathrm are the same as those of the TEXT font (while in ConTeXt \mathrm still uses the kerning and ligatures of the math font, which seems logical)? Compare the following:
LaTeX:
\documentclass{article}
\begin{document}
affinity\par
$\mathrm{affinity}$\par % kerning and ligatures of TEXT mode with math font
\end{document}
ConTeXt:
\starttext
affinity\par
$\mathrm affinity$\par % kerning and ligatures of MATH mode with math font
\stoptext