 This way of defining compatibilism is unproblematic. There are compatibilists who are agnostic about the truth or falsity of determinism, so a compatibilist need not be a soft determinist (someone who believes that it is in fact the case that determinism is true and we have free will). And a compatibilist might believe that we don’t have free will for reasons independent of determinism. But all compatibilists believe that it is at least possible that determinism is true and we have free will. So all compatibilists are committed to the claim that there are deterministic worlds that are free will worlds.