§126.  Inconsistent statements; false swearing

It shall constitute false swearing whenever any person, having made a statement under sanction of an oath, or an equivalent affirmation, required by law, shall thereafter swear or affirm in a manner materially contradictory of or inconsistent with his former sworn or affirmed statement.  It shall not be necessary for the prosecution, in such case, to show which of the contradictory or inconsistent statements was false; but it shall be an affirmative defense that at the time he made them, the accused honestly believed both statements to be true.