unexpected behaviour of expression(sum())

Prof Brian Ripley <ripley@stats.ox.ac.uk> writes:

So my guess on scalable fonts was right.

I suspect this is a problem in how the X server is using Type1 fonts,
specifically in how it thinks they are encoded.  This is why I asked
about the locale: \summation is \345 in the Adobe symbol character set
and \circleplus is \305 which is a u/case to l/case difference in
Latin-1.

Well, the X server is defenseless against people aliasing fonts with
incompatible encodings...

I now recall Kurt had similar problems with gsfonts-x11 last August:

Kurt has found a problem with the last two pages of demo(plotmath) on
X11 (some symbols either wrong or missing completely).

We found

the issue seems to be that gsfonts-x11 has aliases

-adobe-symbol-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific

"-urw-standard symbols l-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific"

"-urw-standard symbols l-regular-r-normal--0-0-0-0-p-0-adobe-fontspecific" "-

urw-standard symbols l-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific"

Any way to ensure that these fonts are not taken by us?

I don't think so, for if I understand that the alias file is lying about
encodings. We specifically added "-adobe-symbol" to overcome problems with
abi symbol fonts at ETHZ, but if that package says the urw fonts in
`standard symbols l' are in adobe symbol and they are not, you are in
trouble.

...as previously noted, it seems (who are you citing there?).