In a post criticizing Wolfram Alpha, Xamuel references the fact that “0!=1”. Coming from a programming background (with C syntax in particular), I thought “Of course 0 doesn’t equal 1, even though the point of this post is to erroneously prove that it does”. But no, what he actually meant to convey is that the factorial of zero is equal to 1. It is unacceptable that I should be confused in such a manner. The exclamation/bang symbol should not be used for negation seeing as how it is commonly used for factorials. I have seen some formal logic using the tilde to indicate negation, and since I don’t that’s used for anything else, I recommend its adoption. I have less frequently seen “><“, by mixing up the greater and lesser symbols to indicate inequality. Not as good as a simple negation.

Hat tip to Ilkka.