I'm not sure if I am understanding this question in my math book correctly. It says to let f be a function from R to R. Without using words of negation, write the meaning of "f is not an increasing function." Does this mean that I just need to rewrite the statement without using the word "not", or am I somehow supposed to prove that f is not an increasing function? If I am supposed to prove this, how would I go about that?

Thanks!