Immoral use of \fontdimen1 in mathematics.

[Stefano Frabetti <stefano@sif.it>]

Hello;

Does somebody know why I don't get the expected result (see below) from
this code:

\font\iupi=cmr10
\fontdimen1\iupi=1.5pt
\fontdimen2\iupi=0pt
\newfam\iopi
\textfont\iopi=\iupi
$
\fam\iopi
abcdefghijklmnop
$
\bye

What I expect is:  1) tex sees letters in mathematics with \fontdimen2=0pt
and so  2) decides to apply as kerning the \fontdimen1,  so that I obtain
a row of cmr10 letters with kerns in between (texbook app. G rules 15&17,
maybe), like this:
     a b c d e f g h i j k l m n o p
What I get is instead
     abcdefghijklmnop
(in cmr10 of course)

------------------
if somebody asks himself ``why?'':  I need a macro to typeset section
titles like this
     s e c t i o n  t i t l e
without having to do it manually like this
     s\,e\,c\,t\,i\,o\,n\ t\,i\,t\,l\,e
and I could find no way of changing the default kerning of a font, except
making a *new* font, of course, which I don't want because I need
something portable and light, if possible.

Of course *any*idea*welcome* !!!

Thanks
Stefano Frabetti