RESHMABEN has joined her husband after four years of a separation neither wanted. She married Shashikant Ramji Padhiar, a factory worker in south London, in Porbander in Gujarat four years ago. And there she remained, as the immigration officials at the British consulate in Mumbai did not give her the visa to come to her husband's home in London. They had been separated not by personal differences but by a British law, the Primary Purpose Rule that required a spouse abroad to prove that the primary purpose of a marriage was marriage and not migration.