sentences:  Sen parted ways with the CPI, following its anti-Congress stand, in 1978, following Indira Gandhi's emergency and subsequent failure in the election.In 1985, Sen joined the Indian Communist Party and when it merged with the All India Communist Party in 1988 to become United Communist Party of India, Sen became its general secretary, a post he held for 15 years till his death.He was married to Vanaja Iyengar, a mathematician, Padma Shri awardee and founder vice chancellor of Sri Padmavati Mahila Visvavidyalayam and at the time of his death, Sen, 74, was a widower and had no children.