I can't seem to find law runes at any store available in f2p, and I need one to do the Lumbridge task of teleporting to Lumbridge. So far I've been slaying Hill Giants hoping for a law rune drop, but I haven't had any luck so far. Are there any better methods of obtaining them available to me? EDIT: Wow, I guess the old stat signature thing I used to have doesn't work anymore. I've been inactive for a long time.
Your logic contradicts itself (and yes, I'm talking about the revised version). It would be better to simply say that by the definition of a set, if x is an element of U, then x is unique. Thus, all Runescape names are unique.