bison 2.0 主要可以用来做语法分析用的，最基本的功能是生成表达式分析程序，做科学计算器可以省事了！-main syntax can be used to do the analysis, the basic function is to generate expression analysis procedures, scientific calculator can save!

用c语言编写的可以在嵌入式环境下运行的科学计算器，在交叉编译环境下编译后，就能在嵌入式linux下运行-C language scientific calculator that can run in the embedded environment, compiled cross-compiler environment, you can run in the embedded Linux

基于Qt界面设计的科学计算器，能完成一半的加减乘除、小数、开方，乘方等-Scientific calculator based on Qt interface design, can complete, decimal, prescribing half of addition, subtraction, multiplication, and division, power, etc