Any of the terms of the agreement of merger or consolidation may be made dependent upon facts ascertainable outside of the agreement; provided, that the manner in which such facts shall operate upon the terms of the agreement is clearly and expressly set forth in the agreement of merger or consolidation. The term "facts" as used in this paragraph, includes, but is not limited to, the occurrence of any event, including a determination or action by any person or body, including the corporation.
Okla. Stat. tit. 18, § 1090.2