The cases environment defined by the ams package clashes with the plain TeX
\cases command due to the implementation of \begin in LaTeX. If the AMS
version was the right thing then I could live with this--unfortunately the AMS
cases environemnt is a plain in the butt to use. Instead of
$f(x)=\cases{0 & if $x$ is irration\cr 1/n & if $x=m/n$ and ${\rm
gcd}(m,n)=1$\cr}$
The AMS cases environemnt turn the second column into amth mode, which is so
consistently what you to do want that completely and utter stupidity is the
only pluasable explanation I can see. So AMS requires me to write the function
as
$f(x)=
\begin{cases}
0 & \hbox{if $x$ is irrational \\
1/n & \hbox{if $x=m/n$ and ${\rm gcd}(m,n)=1$
\end{cases}$
which IMHO is a big move in the wrong direction. FYI $f(x)$ is contiguous if
and only if x is irrational (discontiguous at rational x is trivial and
contiguous for irrational x is not).
--
Duncan (-:
"software industry, the: unique industry where selling substandard goods is
legal and you can charge extra for fixing the problems."
