# FUNCTIONS
# =========

fun double(n)
  n * 2
end

assert double(4) == 8
assert 8 == double(4)

assert double(4) != 10
assert 9 != double(4)

assert double(double(double(3))) == 24

fun a()
  return 45
end

assert a() == 45

fun b()
  return 27
  return 32
end

assert b() == 27

fun max(m, n)
  if m > n then
    return m
  end
  return n
end

assert max(7, 3) == 7
assert max(7, 9) == 9

# RECURSIVITY
# ===========

fun fac(n)
  if n == 0 then
    return 1
  end

  return n * fac(n - 1)
end

assert fac(5) == 120

fun fib(n)
  if n == 0 or n == 1 then
    return 1
  end

  return fib(n - 2) + fib(n - 1)
end

assert fib(6) == 13