Kirshenbaum v. Pennsylvania Board of Law Examiners

How later courts describe this case

• approving injunction against foreign breach of contract action where antitrust implications of agreements were being litigated in the U.S.
• payments of contractors to pension funds were not extracted by unlawful means where trustees enforced delinquency clause involving subcon tractor contributions in master labor agreement against contractors
• court has power to enjoin party from bringing compulsory counterclaim as subsequent federal action