Its really simple but its kinda like a visual illusion. Your so amazed that they could prove a=b to be false that its hard to find the error.
Of course it's simple. Most things are simple once you understand the answer. The term "complicated" (which is an acceptable antonym for "simple," I think) describes something beyond one's comprehension or is barely understandable. I don't think anyone here would have a problem understanding [a - b = 0] when [a = b]. It becomes simple / obvious after the connection between those two statements are made; until then, it is
not intuitively obvious.
If your brain is run by any sort of logic, you'll realize that there's obviously something wrong with this system. If you're interested or at least persistent, it's a matter of minutes (or seconds, even) of re-reading the equations. The people who don't figure it out are the ones who decide it's impossible for them to understand.
