let ll1 = string_of_int (List.length l1) in
let ll2 = string_of_int (List.length l2) in
let diff = string_of_float (after -. before) in
- prerr_endline ("UNION(" ^ ll1 ^ "," ^ ll2 ^ "): " ^ diff ^ "s") ;
- flush stderr ;
+ print_endline ("UNION(" ^ ll1 ^ "," ^ ll2 ^ "): " ^ diff ^ "s") ;
+ flush stdout ;
res
;;