\(A \subset B\text{.}\)
\(B \subset A\text{.}\)
\(B \in C\text{.}\)
\(\emptyset \in A\text{.}\)
\(\emptyset \subset A\text{.}\)
\(A \lt D\text{.}\)
\(3 \in C\text{.}\)
\(3 \subset C\text{.}\)
\(\{3\} \subset C\text{.}\)