This is LaTeX code:
[latex]
\supseteq : \newline pps. \, \exists a \in A \, t.d. \, a\notin \bigcup \limits _{x \in A} [x]_E \newline a \in [a]_E \subseteq \bigcup \limits _{x \in A} [x]_E \Rightarrow \Leftarrow \newline
[/latex]