Element of Ordered Set of Topology is Dense iff is Everywhere Dense

Theorem
Let $T = \left({S, \tau}\right)$ be a topological space.

Let $P = \left({\tau, \preceq}\right)$ be an ordered set where $\mathord\preceq = \mathord\subseteq \cap \left({\tau \times \tau}\right)$

Let $A \in \tau$.

Then $A$ is a dense element in $P$ $A$ is everywhere dense.

Sufficient Condition
Assume that
 * $A$ is a dense element in $P$.

By Bottom in Ordered Set of Topology:
 * $\bot_P = \varnothing$

We will prove that
 * for every open subset $U$ of $S$: $U \ne \varnothing \implies U \cap A \ne \varnothing$

Let $U$ be an open subset of $S$ such that
 * $U \ne \varnothing$

By definition of open set:
 * $U \in \tau$

By definition of topological space:
 * $U \cap A \in \tau$

By Meet in Inclusion Ordered Set:
 * $U \wedge A = U \cap A$

Thus by definition of dense element:
 * $U \cap A \ne \varnothing$

By Characterization of Closure by Open Sets:
 * $A^- = S$

where $A^-$ denotes the topological closure of $A$.

Hence $A$ is everywhere dense.