> the statement "P implies Q" is considered true if P can never be true. As an example, let P be "George Washington was a woman" and Q be "Queen Elizabeth is a man". Then the statement "If GW was a woman, then QE is a man" is considered to be a true statement.

> I have a friend who refuses to accept that such a statement should be considered "true".

This is a weird thing to refuse to accept, since it is an ordinary part of vernacular English, a common way of dismissing an assertion as false.

"If that guy graduated high school, I'm the King of England."