| 閏年か？ |

閏年か？ := [:int |
	(int isDivisibleBy: 4)
		and: [(int isDivisibleBy: 100) not or: [int isDivisibleBy: 400]]].

閏年か？ value: 1900.   "=> false "
閏年か？ value: 2000.   "=> true "
閏年か？ value: 2008.   "=> true "
閏年か？ value: 2100.   "=> false "