4.—In this Act and in every Act of the Oireachtas passed after the commencement of this section—

(a) a reference, however expressed, to a person whose parents have not married each other shall, unless the contrary intention appears, be construed as including a reference to a person whose parents are or have been married to each other but between whom there has been no subsisting marriage at any time during the period of ten months before the person’s birth, or during the persons’s lifetime, and

(b) a reference, however expressed, to a person whose parents have married each other shall, unless the contrary intention appears, be construed as excluding a reference to a person in respect of whom paragraph (a) of this section applies.