Xerox Corporation (Xerox) (defendant) operated in two markets involving photocopiers. In one market, Xerox manufactured and sold photocopiers. In a second market, Xerox competed with independent service organizations (ISOs) to service and repair photocopiers. ISOs needed to purchase photocopier replacement parts and diagnostic software from Xerox to compete in the services-and-repair market. Xerox held intellectual property rights in patented photocopier parts and copyrighted software for photocopiers. Starting in 1984, Xerox enacted a policy of not selling parts or licensing software to ISOs. CSU, LLC (CSU) (plaintiff), an ISO, sued Xerox for violating the Sherman Act. CSU alleged that the goal of Xerox’s parts policy was to eliminate competition from ISOs in the services-and-repair market. The district court granted Xerox’s motion for summary judgment. CSU appealed.