Example

For example, in defining a graph, one might have once written:

##
$a = -2;
$b = -2;

## This expression will be correctly parsed by FEQ
$f = FEQ("$a*x^2 ? {$b}*x  for x in [$xmin, $xmax] using color:blue
and weight:2");

in an attempt to resolve problems with the sign of $b and the preceding operator.

Now you should just write

$f = FEQ("${a}x^2 + ${b}x for x in [$xmin, $xmax] using color:blue
and weight:2");

and FEQ will take care of adjacent +- or -+ or - signs with no prompting.