What is the current factual position on GB in Pak constitution ?
Article 2 of Constitution.
The territories of Pakistan shall comprise:-
(a) the Provinces of 2[Balochistan] 2, the 3[Khyber Pakthunkhwa] 3, the Punjab and 4[Sindh] 4 ;
(b) the Islamabad Capital Territory, hereinafter referred to as the Federal Capital;
(c) Federally Administered Tribal Areas; and
(d) such States and territories as are or may be included in Pakistan, whether by accession or otherwise.