(a) Proof of guilt beyond a reasonable doubt is sufficient for conviction under this act,¹ and it shall not be necessary also that proof be by a particular number of witnesses or by documentary or other type of evidence.

(b) Lack of materiality of the statement is not a defense but the degree to which a perjured statement might have affected some phase or detail of the trial, hearing, investigation, deposition, certification or declaration shall be considered, together with the other evidence or circumstances, in imposing sentence.

(c) In a prosecution for perjury by contradictory statements, as defined in Section 496 of Title 21, it is unnecessary to prove which, if any, of the statements is not true.