proof by contrapositive中文什么意思

反证法

• proof:    n. 1.证明；证据；【法律】证件； ...
• contrapositive:    adj. 对照的；针对的。
• contrapositive form:    相反位置形式

百科释义

In logic, the contrapositive of a conditional statement of the form "if A then B" is formed by negating both terms and reversing the direction of inference. Thus, the contrapositive of the statement "if A, then B" is "if not B, then not A.