Huge thanks to you 
I checked every parenthesis and now it works perfectly this is the final code that works
;version 4
;type generate
(defun tone ()
(mult (osc (hz-to-step 1000) 0.25)
(pwlv 0 0.02 1 0.23 1 0.25 0)
(db-to-linear (* -5 (+ 1 (random 10))))))
(defun rest ()
(s-rest (+ 1.8 (rrandom))))
(seqrep (i 200)
(seq (rest) (tone)))
How can I make it up to you ?