!! +exec+ +var+ +string+
$lst_tit rawmath$lst_titend$type_both
  $(lst_syntax)rawmath $emph expr$emphend</tt>
  $lst_mean 把可能含有常见错误的数学式 $emph expr$emphend 翻译成机器能理解的数学式. <br/>
  它把 $emph (x+1)(x-1)$emphend 变成 $emph (x+1)*(x-1)$emphend,
  把 $emph 5x^3$emphend 变成 $emph 5*x^3$emphend, 等等.


