程序中逻辑表达式从终端输入,　　演示程序以用户与计算机的对话方式执行 根据用户输入的逻辑表达式,判别其是重言式还是矛盾式,或两者都不是 若都不是则与用户交互.-Process logical expression from the terminal input, demo program to the user' s dialogue with the computer implementation　in accordance with user input logic expressions are discriminant its tautology or contradiction, or neither is　if not with the user interaction.