A nonsim sign is a feature that tends to attach to nonsims. More precisely, it is a feature that a nonsim is more likely to have than a sim. In the world where all sims get a “You are a sim” signal, the absence of such a signal is a nonsim sign. If we know we have a nonsim sign, then even if we know that 99 percent of beings are sims, we should be less than 99 percent confident that we are sims.
