http://sdmeta.gforge.inria.fr/FreeBooks/LittleSmalltalk/ALittleSmalltalk.pdf
ʂ̃TCgɃWv悤ƂĂ܂BXΏL̃NNbNĂ
UPLIFTōLȂő̌܂傤IKȉ{Ct܂I