ThmDex – An index of mathematical definitions, results, and conjectures.
Binary intersection is a lower bound to each set in the intersection
Formulation 0
Let $A$ and $B$ each be a D11: Set such that
(i) $A \cap B$ is the D76: Set intersection of $A$ and $B$
Then
(1) \begin{equation} A \cap B \subseteq A \end{equation}
(2) \begin{equation} A \cap B \subseteq B \end{equation}
Proofs
Proof 0
Let $A$ and $B$ each be a D11: Set such that
(i) $A \cap B$ is the D76: Set intersection of $A$ and $B$