I hope everyone understands that anti-realism is not a statement that "reality is not real", i.e. it is not nihilism, but it is a statement that the predication of existence is relative to the theory which gives it (this predication) validity, so to say. ETA: I think I'll withdraw my comments here regarding "anti-realism" because it seems the term is not defined this way... See Anti-realism and metaphysical nihilism.