Let $S$ be a subspace of topological space $X$.
Show that the closure of $S$, the set of contact points, is indeed closed.
I need to prove that the closure is closed but I don't know how to go about it.
Let $S$ be a subspace of topological space $X$.
Show that the closure of $S$, the set of contact points, is indeed closed.
I need to prove that the closure is closed but I don't know how to go about it.