Explain Section 139 concerning persons subject to certain Acts.
Section 139 states that no person subject to the Army Act, the Army Act, 1950 (46 of 1950), the Naval Discipline Act, the Indian Navy (Discipline) Act, 1934 (34 of 1934), the Air Force Act, or the Air Force Act, 1950 (45 of 1950), is subject to punishment under this Code for any of the offences defined in this Chapter Number. [Chapter 7, Section 139]