definiens: means ( a ) any and all Improvements to the Joint Technologycreated, conceived or reduced to practice, and, in the case of patentable Improvements, Invented, solely by [COMPANY], its Affiliates, agents or by Third Parties acting on their behalf, whileperforming activities under this Agreement ; and ( b ) any and all Improvements to the CelgeneTechnology created, conceived or reduced to practice, and, in the case of patentableImprovements, Invented, solely by either Party, its Affiliates, agents or by Third Parties acting ontheir behalf or jointly by the Parties, their respective Affiliates, agents or by Third Parties acting ontheir behalf, while performing activities under this Agreement ; provided, however, that CelgeneImprovements shall not include any Improvement that is an [COMPANY] Improvement or JointImprovement