Let's have good clean sophistical fun. Consider the sentences:
- He can not come to the phone right now.
- He cannot come to the phone right now.
- Claims (1) and (2) are different.
- Two things that differ by nothing are the same.
- Claims (1) and (2) differ by a space.
- A space is nothing.
- Therefore, claims (1) and (2) are the same and different.
- Therefore, the sky is green. (By Explosion)
(The lesson, of course, is that one shouldn't identify symbols with physical objects, though some symbols are implemented by a kind of physical object.)