parameter (list string);
storage unit;
return (list string);
code {CADR; DIP {NIL string}; SWAP; PUSH bool True;
      # INV: BOOL : ORIG_LIST : REV_LIST : []
      LOOP {IF_CONS {DIP {SWAP}; CONS; SWAP; PUSH bool True} {NIL string; PUSH bool False}};
      DROP; UNIT; SWAP; PAIR};