Because you never change the states of your variables, proving your program is much easier.
由于从来没有改变变量的状态，所以证明您的程序非常简单。
2
The model and program were proved right through theory analysis and examples proving.
通过理论研究和实例验证，证明了模型和程序是正确的。
3
The article USES the proving of deduction theorem to give general program of construction theorem proving, and adding a piece of simplification command. The program is gotten strict and exercisable.