Соединить три элемента в одну строку - Lisp

(progn
         (time
          (and (join-strings *test*) ()))
         (time
          (and (join-str *test*) ())))
Evaluation took:
  0.031 seconds of real time
  0.030000 seconds of total run time (0.030000 user, 0.000000 system)
  96.77% CPU
  72,880,559 processor cycles
  4,000,032 bytes consed
  
Evaluation took:
  0.034 seconds of real time
  0.034000 seconds of total run time (0.034000 user, 0.000000 system)
  100.00% CPU
  81,329,412 processor cycles
  4,032,656 bytes consed