Babrak Karmal befriended fellow inmate Mir Akbar Khyber, who introduced Karmal to Marxism. Karmal changed his name from Sultan Hussein to Babrak Karmal, which means "Comrade of the Workers'" in Pashtun, to disassociate himself from his bourgeois background. When he was released from prison, he continued his activities in the student union, and began to promote Marxism. Karmal spent the rest of the 1950s and the early 1960s becoming involved with Marxist organizations, of which there were at least four in Afghanistan at the time; two of the four were established by Karmal. When the 1964 Afghan Provisional Constitution, which legalised the
Prime Minister of Singapore from the Cabinet in 2011 but remained as members of Parliament. The role of Deputy Prime Minister is the second-highest post and senior Cabinet Minister in Singapore. The holder will sometimes assume the role of Acting Prime Minister when the PM is temporarily absent. Since the mid-1980s, Singapore has usually had two Deputy Prime Ministers at a time. Only Ong Teng Cheong and Tony Tan served under more than one Prime Minister during their time as Deputy Prime Minister. In the cabinet of Goh Chok Tong in the 1990s to 2004, current Prime Minister Lee Hsien Loong and former President