16.  Fractions

      To make a fraction, use the word over: a+b over 2c =1
gives

The line is made the right length and positioned automatically. Braces can be used to make clear what goes over what: {alpha + beta} over {sin (x)}
is

What happens when there is both an over and a sup in the same expression? In such an apparently ambiguous case, EQN does the sup before the over, so -b sup 2 over pi
is instead of The rules which decide which operation is done first in cases like this are summarized in section 23. When in doubt, however, use braces to make clear what goes with what.