let number_of_common_line_between_all_zones (x : float) (y : float) : int =
let rec aux infos_zones res =
match infos_zones with [] -> (*prerr_string ";prerr_float((res /. !yDelta)); prerr_string ";*)(int_of_float (res /. !yDelta))
|(((click_x,click_y),z)::ls) ->
if(click_x<>x && click_y=y)
then aux ls (max res ((max_l z) -. (min_l z)))
else aux ls res;
in aux (!infos_zones) 0.