up & up / dn & dn

This isn't a syntax crystal, a word pyramid, or anything like those. This is something a little different. Sometimes my mind wanders off into uncharted territory and I find myself here, seeing this image in my mind. Seems simple enough, a line with arrows at both ends, right? True, but it is also a visual palindrome, meaning you flip the book upside down and it'll say the same thing; fun fact, if you look carefully the bottom it looks like it says "dn & dn". The reality is that it's "up & up", just upside down to read "dn & dn", which happens to be it's exact opposite meaning. Wait what? Turn the book upside down and check it out. Pretty rare to see a word that when physically flipped upside down becomes the negation of the original word. What words can you think of that can do this?