 It is clear that comprehension allows the definition of finite sets: our set of men {Tom, Dick, Harry} can also be written \(\{x \mid {}\) \(x = \textit{Tom}\) \({}\lor{}\) \(x = \textit{Dick}\) \({}\lor{}\) \(x = \textit{Harry}\}\). It also appears to allow for the definition of infinite sets, such as the set \((\{x \in \mathbf{Q} \mid x \lt 0 \lor x^2 \lt 2\}\) mentioned above in our definition of the square root of 2.