Здравствуйте. Только начинаю изучать lisp. Помогите пожалуйста найти ошибки в коде:

(defun C:der7 ()
(setq slad vvod vid centr razm
spp (list slad vvod vid razm ))
(slad)
(vvod)
(vid)
(centr)
(razm)

)
(command "_vslide" )

(defun vvod ()
(setq L (getdist "\nВВЕДМТЕ РАЗМЕР L:"))
(setq В (getdist "\nВВЕДИТЕ РАЗМЕР B:"))
(setq С1 (getdist "\nВВЕДИТЕ РАЗМЕР С:"))
(setq L1 (getdist "\nВВЕДИТЕ РАЗМЕР L1:"))
(setq В1 (getdist "\nВВЕДИТЕ РАЗМЕР В1:"))
(setq D (getdist "\nВВЕДИТЕ РАЗМЕР D:"))
(setq S (getdist "\nВВЕДИТЕ ТОЛЩИНУ ПЛАСТИНЫ S:"))
)
(defun vid ()
(command "_redrawall")
(command "_limits" " " (list (+ L 200) (+ В 100)))
(command "_zoom" "_all")
(command "_line" 100 50 " " (list 100 (+ 5O B))
(list (+ 100 L) (+50 B))
(list (+ 100 L) 5O) "_c")
(command "_circle" (list (+ 100 L1) (50 B1)) "_d" D)
(command "_copy" "_l" " " (list (+ 100 L1) (+ 50 В1)) (list (+ 100 L1 C1) (+ 50 B1)))
)
(defun centr ()
(command "_linetype" "_set" "center" "")
(command "_line" (list 95 (+ 50 B1)) (list (+ 100 L 5) (+ 50 B1)) "")
(command "_line" (list (+ 100 L1) 45) (list (+ 100 L1) (+ 50 B5)) "")
(command "_line" (list (+ 100 L1 C1) 45) (list (+ 100 L1 C1) (+ 50 B 5)) "")
)

(defun razm ()
(command "_linetype" "_set" "continuous" " ")
(command "_dimlinear" 100 50 " " (list (+ 100 L1) 50) (list (+ 100 (/ L1 2)) 35))
(command "_dimlinear" 100 50 " " (list (+ 100 L) 50) (list (+ 100 (/ L 2)) 20))
(command "_leader" (list (+ 100 (- L 10)) (+ 50 10)) (list (+ 100 L 20) (+ 50 B1))
"" (strcat" S=" (itoa (fix S)) "*" " ")
)