Unity communications corp. resold phone services provided by cingular pursuant to a reseller agreement that included an arbitration clause. unity sued cingular in federal district court, alleging breach of contract. the parties engaged in pretrial activity, and cingular filed a motion for summary judgment regarding a letter agreement between unity and cingular. the district court denied the motion for summary judgment, and on appeal the fifth circuit affirmed the district court's decision. on remand before the district court, cingular moved the court to compel arbitration. the district court ruled that cingular had waived its right to arbitration by participating in the litigation and waiting three years to raise the arbitration argument. do you think the appellate court agreed? why? [unity communications corp. v. cingular wireless, 256 fed. app. 679 (5th cir. 2007).]