let a = ref 0

let foo x y z = a := !a + 3; x + y + z

let foo2 = function x -> incr a; function y -> incr a; function z -> incr a; x + y + z

let main () =
    let p x = Printf.printf "%d\n" x; x in
    foo (p 0) (p 1) (p 2);
    foo2 (p 0) (p 1) (p 2)

let _ = main ()