Given an equation for an asymptote of \[y=$a\cdot x+\frac{1}{x-$b}\]
$first=&compareequations('y',"$a*x",$submission,1);
if ($first=~/^Error/) { return 'BAD_FORMULA'; }
if ($first=~/true/) { return 'EXACT_ANS'; }
$second=&compareequations('x',$b,$submission,1);
if ($second=~/^Error/) { return 'BAD_FORMULA'; }
if ($second=~/true/) { return 'EXACT_ANS'; }
return 'INCORRECT';