foo.clj

(defn optionFourWorkOut []
  (println "Enter user name")
  (let [use-input (read-line)
        user-name-id (first
                      (for [x (range @customer-size)
                            :while (= (compare user-input (get (get customer-list x) 1)) 0)]
                        (get (get customer-list x) 0)))
        user-product-id-and-quantity (vec (for [y (range @sales-size)
                                                :while (= (compare user-name-id (get (get sales-list y) 1)) 0)]
                                            [(get (get sales-list y) 2) (get (get sales-list y) 3)]))
        arr (vec
             (for [z (range @product-size)
                   :while (compare (get (get user-product-id-and-quantity z) 0) (get (get product-list z) 0)) 0]
               [(get (get product-list z) 2)]))]
    ;; do whatever with values here
    
    ))