Talk:Image of Subset under Relation equals Union of Images of Elements

In the proof that $\mathcal R \left[{X}\right] \subseteq \bigcup_{x \in X} \mathcal R \left({x}\right)$, I found the usage of $x$ and $y$ in the following line a little bit confusing:
 * $\left({x, y}\right) \in \bigcup_{x \in X} \left\{{ \left({x, y}\right) \in \mathcal R }\right\}$

On the LHS of the $\in$, $y$ is an arbitrarily chosen value in $\mathcal R \left[{X}\right]$ and $x$ is the value we chose that relates to $y$ under $\mathcal R$. However, on the RHS of the $\in$, the letter $x$ is reused for iterating through all the values in $X$. Would you mind if I changed the $x$ to a $s$ and the $y$ to a $t$ on the LHS? The first few lines would read:

--Cjhanrahan (talk) 04:00, 1 December 2017 (EST)


 * No, because what you have written does not seem to make any sense. --prime mover (talk) 13:51, 1 December 2017 (EST)


 * Haha ok, I'll leave it as is.--Cjhanrahan (talk) 04:01, 2 December 2017 (EST)