let
    var i := 69

    function do_something() = let var a := 1 in a := a + 1 end
    function do_something_else() = print_int(1 <> 2)

    function print_a_number(k: int) = print_int(k)
    function conditional_print(value: int) = (print_a_number(value); print_a_number(i))

    function main_callback() = (
        do_something();
        print_a_number(i);
        do_something_else();
        print("\n");
        conditional_print(9)
   )
in
    main_callback()
end