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数学不知道种族或地理界限;对于数学来说,文化世界是一个国家。
生活中唯一真正的失败是不忠于自己所知道的最好的东西。
There are no hard distinctions between what is real and what is unreal, nor between what is true and what is false. A thing is not necessarily either true or false; it can be both true and false.