--- include(module ... )

    ꤵ줿⥸塼(᥽åɤ饹ѿ)ɲäޤ
    self ֤ޤ
    include ¿ŷѾѤ Mix-in ¸뤿
    ˻Ȥޤ

        class C
          include FileTest
          include Math
        end

        p C.ancestors

        # => [C, Math, FileTest, Object, Kernel]

    ⥸塼εǽɲäϡ饹ηѾطδ֤ˤΥ⥸塼뤬
    뤳ȤǼ¸Ƥޤäơ᥽åɤõʤɤϥѡ
    饹ͥ褵ɲä⥸塼뤫õޤ(
    ancestors η̤᥽åõνǤ)

    Ʊ⥸塼ʾ include ܰʹߤ̵뤵ޤ

        module Foo;                    end
        class  Bar;       include Foo; end
        class  Baz < Bar; include Foo; end  # <-  include ̵

        p Baz.ancestors  # => [Baz, Bar, Foo, Object, Kernel]


    ⥸塼ηѾط۴ĤƤޤ褦 include Ԥȡ㳰
    ArgumentError ȯޤ

        module Foo; end
        module Bar; include Foo; end
        module Foo; include Bar; end

        => -:3:in `append_features': cyclic include detected (ArgumentError)
                from -:3:in `include'
                from -:3

    ruby 1.7 feature: ʣΥ⥸塼ꤷ硢Ǹ
    ΰս include Ԥޤ

