Using $reverse will reverse the sentence by words.
Example: $reverse(I have a large fox.) --> fox. large a have I

Using $reveret will reverse the sentence entirely by all the words including letters.
Example: $reverset(Hello) --> olleH

I didn't make $reverset however I am posting this here for others.

alias reverse { return $regsubex($1-,/([^\s]+)/g,$regml($calc($regml(0) - \n + 1))) }

alias reverset { var %o = $len($1-),%i
while (%o) { %i = $+(%i,$replace($mid($1-,%o,1),$chr(32),$chr(160))) | dec %o } 
if ($isid) return %i | else say %i }