Autolisp: o cilindro e a intersecção da recta

(command "circle" "0,0,0" "1")
(setq ent_cir1 (entget(entlast)))
(command "circle" "0,0,3" "1")
(setq ent_cir2 (entget(entlast)))
;(setvar 'pdmode 34)
(command "vpoint" "0.3,-1,1")
(command "regen")
(command "line" "2,-1,0" "-2,1,3" "")
(setq ent_line (entget (entlast)))
(setq ent_poi_cir1 (polar (cdr (assoc 10 ent_cir1)) (angle (list 0 0 0) (list 2 -1 0)) 1))
(setq ent_poi_cir2 (polar (cdr (assoc 10 ent_cir1)) (angle (list 0 0 0) (list -2 1 0)) 1))
;(command "line" ent_poi_cir1 c "")
;(command "line" ent_poi_cir2 (cdr (assoc 10 ent_poi)) "")
(setq ent_poi_fin1 (inters ent_poi_cir1 "@0,0,300" (list 2 -1 0) (list -2 1 3)))
(setq ent_poi_fin2 (inters ent_poi_cir2 "@0,0,300" (list 2 -1 0) (list -2 1 3)))
(command "point" ent_poi_fin1)
(command "point" ent_poi_fin2)
(print (list ent_poi_fin1))
(print (list ent_poi_fin2))

(list (last (cdr (assoc 10 ent_cir2)))
(reverse(cdr (reverse a)))