每个元素可用一个符号表示。 Each element may be represented by a symbol.
一种图形表示法，其中使用一些符号表示诸如操作、数据、流向和设备之类的项目，以便定义、分析或解决问题。同flowdiagram。 A graphical representation in which symbols are used to represent such things as operations, data, flow and equipment, for the definition, analysis, or solution of a problem.
