<span>In logic, contraposition is a law that says that a conditional statement is logically equivalent to ... For example, if we want to prove that every girl in the United States (A) has brown hair (B), we can try to directly prove A → B {\displaystyle A\to B} A\to B ... A proposition Q is implicated by a proposition Pwhen the following ...</span><span> </span>
You can see it with an example. Let p and q be sets and let p be inside of q (p⇒q). Then, If something is not in q it will not be in p either (¬q ⇒¬p).
