<> (explode ?*) (str (?*)) <> (reverse (str (?h ?t))) (reverse/l ?t (?h)) <> (reverse (str (?h))) (?h) <> (reverse/l (?h ?t) ?l) (reverse/l ?t (?h ?l)) <> (reverse/l (?h) ?l) (str (?h ?l)) <> (implode str ?*) (?*) (implode reverse (explode hello))