Zorn's Lemma implies Hausdorff's Maximal Principle

Theorem
Let Zorn's Lemma be accepted as true.

Then Hausdorff's Maximal Principle holds.

Proof
Recall Zorn's Lemma:

Recall Hausdorff's Maximal Principle:

It is seen directly that Hausdorff's Maximal Principle is a special case of Zorn's Lemma where the ordering is the subset relation.