be joined as a party if necessary to prosecute the action or proceeding, and shall provide all reasonable cooperation, including any necessary use of their name, required to prosecute such action or proceeding. In such instance, RemainCo shall control any such action or proceeding and negotiations for its settlement and compromise and shall have sole discretion regarding the settlement or compromise thereof. In connection with the foregoing, SpinCo may, at its option, elect to assume and pay its and RemainCo's out-of-pocket costs incurred in connection with such litigation or proceeding undertaken by RemainCo, including, without limitation, attorney's fees. SpinCo will provide prompt written notice to RemainCo, in any event no later than thirty (30) days after receipt of RemainCo's notice of its determination to initiate, prosecute and control such action or proceeding in the SpinCo Core Field, of its determination to elect to assume and pay the applicable costs or to decline to pay assume and pay the applicable costs. In the event SpinCo does not elect to assume and pay the costs associated with RemainCo's initiation, prosecution and control of such action or proceeding in the SpinCo Core Field, RemainCo shall assume and pay its and SpinCo's out-of-pocket costs incurred in connection with such litigation or proceeding undertaken by RemainCo, including, without limitation, attorney's fees. Any recovery obtained as a result of such proceeding in the SpinCo Core Field shall be retained by (i) SpinCo in the event that SpinCo assumed and paid the applicable costs of the litigation or proceeding or (ii) RemainCo in the event that RemainCo assumed and paid the applicable costs of the litigation or proceeding in accordance with this Section 8.3(a)(i). (ii) If RemainCo does not exercise its right to enforce any applicable Licensed RemainCo Intellectual Property in the SpinCo Core Field, RemainCo shall