How to write neither ___ nor ___ in First Order Logic?

Question

If X exists, it is neither Y nor Z.

Would this be written as X ⇒ ¬Y ∨ ¬Z ?

Or would it be X ⇒ ¬(Y ∨ Z) ?

Answer 1

\begin{equation} (\exists x \in S)(\exists y, z \in S) \Rightarrow x \neq y \wedge x \neq z \end{equation}

Where S is some arbitrary set