Wang and Nyima state that after the official title "Education Minister" was granted to Tai Situ Changchub Gyaltsen (1302–1364) by the Yuan court, this title appeared frequently with his name in various Tibetan texts, while his Tibetan title "Degsi" (sic properly sde-srid or desi) is seldom mentioned. What title was given by the Yuan court to Tai Situ Changchub Gyaltsen ?