I. A person is guilty of a class B felony if in any official proceeding: (a) He makes a false material statement under oath or affirmation, or swears or affirms the truth of a material statement previously made, and he does not believe the statement to be true; or(b) He makes inconsistent material statements under oath or affirmation, both within the period of limitations, one of which is false and not believed by him to be true. In a prosecution under this section, it need not be alleged or proved which of the statements is false but only that one or the other was false and not believed by the defendant to be true.II. "Official proceeding" means any proceeding before a legislative, judicial, administrative or other governmental body or official authorized by law to take evidence under oath or affirmation including a notary or other person taking evidence in connection with any such proceeding. "Material" means capable of affecting the course or outcome of the proceeding. A statement is not material if it is retracted in the course of the official proceeding in which it was made before it became manifest that the falsification was or would be exposed and before it substantially affected the proceeding. Whether a statement is material is a question of law to be determined by the court.1971, 518:1, eff. Nov. 1, 1973.