Let's say there was a fractal set that included members that has a 'life' property, but that we had no simple test or definition. Looking at the boundaries of w

Let's say there was a fractal set that included members that has a 'life' property, but that we had no simple test or definition. Looking at the boundaries of what's in or outside the set would be futile as we could indefinitely split hairs and find examples that are successively closer to being in but actually out. This isn't to say that such a set doesn't exist.