vector font question

[Peter Brooker <ra5589(at)email.sps.mot.com>]

I am doing some equations using vector fonts and cannot seem to find the
horizontal division line to express a fraction. The best I can do is the
minus sign. For example, consider

plot,[0,1]
ss='!s-------!r!s!a(y2-y1)!r!b(x2-x1)'
xyouts,.1,.5,ss,charsize=2

The minus sign looks terrible. What is the code for the division line?

thanks-Peter Brooker