Shanghai, June 27: Prime Minister Atal Bihari Vajpayee today left for home after conclusion of his "cordial and fruitful" six-day official visit to China. During his visit, the first by an Indian Prime Minister in a decade, Vajpayee signed a historic trade protocol opening border trade between the two countries from the Nathu La pass in Sikkim and a joint declaration pledging to resolve the vexed border problem speedily. Bureau Report