Minor wording: e^x is a function whose derivative is equal to itself, or the value of whose derivative is equal to its own value. This might be considered the kind of excessive precision that obscures rather than clarifies (as would be, for example, writing x ↦ e^x in place of just e^x), but lots and lots of confusion can result (especially in a function-analytic setting) from failing to distinguish between a function and its values.