first = fn (F) {
  F()
}

second = fn () {
  io.format("hello~n")
}

@public
run = fn () {
    # passing the function specifying the name and arity
    # arity: the number of arguments it accepts
    first(fn second:0)

    first(fn () { io.format("hello~n") })

    # holding a reference to the function in a variable
    F1 = fn second:0
    F2 = fn () { io.format("hello~n") }

    first(F1)
    first(F2)
}