I have a suggestion to add a new operator !==
We all know that exists an operator == that returns equal affirmation between $1 and $2 and != that returns affirmation that is not equal. Also,is present === regarding case-sensitive affirmation, but !== negative case-sensitive affirmation doesn't!
We can avoid this operator (!==) using:
if ($1 === $2) command | else command..
but when it's concerning a long-range scripts, using If-then-else statements can make headaches. In some cases, is good to have:
if ($1 !== $2) halt
then to add If-then-else statements.