The 'Root-' Sarvâstivādas 說一切有部. A school derived from the Sthavira 上座部 school that developed around the second century and that influenced subsequent philosophical developments before declining around the seventh century. It was later called mūla, because many schools were derived from it. (Tib. (གཞི་ཐམས་ཅད་ཡོད་པར་སྨྲ་བའི་སྡེ༏). Transliterated as 薩婆多部.