RosettaCodeData/Task/Fibonacci-sequence/NGS/fibonacci-sequence.ngs

F fib(n:Int) {
	n < 2 returns n
	local a = 1, b = 1
	# i is automatically local because of for()
	for(i=2; i<n; i=i+1) {
		local next = a + b
		a = b
		b = next
	}
	b
}