A pleading must state as a counterclaim any claim that—at time of service—the pleader ahs against an opposing party if the claim:
Arises out of the transaction or occurrence that is th esubject matter of the opposing party's claim; and
does not require adding another party over whom the court cannot acquire jurisdiction.
The pleader need not state the claim if:
when the action was commenced, the claim was the subject of another pending action; or
the opposing party sued on its claim by attachment or other process that did not establish personal jurisdiction over the pleader on that claim, and the pleader does not assert any counterclaim under this rule.
(b) Permissive Counterclaims
A pleading may state as a counterclaim against an opposing party any claim that is not compulsory.