<> (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 ?*) (?*) <> ((read)) (?:) <> (empty-register) (?x) <> (explode ?*) (str (?*)) <> (eq ?x ?x) (#t) <> (eq ?x ?y) (#f) (implode reverse (explode hello)) (read) (explode hello) empty-register (eq abc abc) (eq abc def)