逻辑表达式从终端输入，长度不超过一行。逻辑运算符包括“｜”、“＆”和“～”，分别表示或、与和非，运算优先程度递增，但可有括号改变，即括号内的运算优先。逻辑变元为大写字母。表达式中任何地方都可以含有多个空格符。

若是重言式或矛盾式，可以只显示“True Forever”或“False Forever”，否则显示“Satisfactible”以及变量名序列，与用户交互。若用户对表达式变元取定一组值，程序就求出并显示逻辑表达式的值。-logic expression from the terminal input, not longer than his. Logical Operators including "|","&" and "~", or said, and non - computational priority increase but change is in brackets, brackets computing priority. Logic variable element for capital letters. Anywhere expressions can contain multiple address spaces. If tautology or contradiction. it only shows that "Forever True" or "False Forever" it shows that the "Satisfactible" and the sequence of the variable name, and user interaction. If users of expression variables from a set of values, the procedures calculated logic and show the value of the expression.