语义项也许会出现在一系列的图表中，这样符号对程序就没有什么具体的意义了。
A semantic item may appear on any number of diagrams, so notation rarely has any concrete meaning to an application.
从古至今，这种改变在读写形式的进化中早已屡见不鲜。 在不到十万年前，人类先民才第一次把有意义的符号刻画出，比如在洞壁上记录下月相或画上动物。
It was less than 100, 000 years ago that our human predecessors first made meaningful marks on surfaces, notating the phases of the moon or drawing animals on cave walls.
只是通过符号和概念看待事物，因此不会忽视事物的相关价值和生活和关系中的实践意义。
Through seeing things as no more than symbols or concepts a person does not thereby ignore their relative value and their practical significance in his life and relationships.
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