It is the first letter of Indic alphabets and, as a sound on its own, can be seen as the most neutral and basic of speech sounds. Many sutras are known by the number of lines, or "ślokas", that they contain. This sutra is called the "Lotus Sutra", "White Lotus Sutra", "Sutra of the White Lotus" or "Sutra on the White Lotus of the Sublime Dharma"; Sanskrit: "Saddharma-pundarīka-sūtra"; 妙法蓮華經 Cn: "Miàofǎ Liánhuā Jīng"; Jp: "Myōhō Renge Kyō". Probably written down in the period 100 BCE – 150 CE, the "Lotus Sutra" proposes that the three "yānas" ("śrāvakayāna", "pratyekabuddhayāna" and "bodhisattvayāna") are not in fact three different paths leading to three goals, but one path, with one goal. This doctrine defines the enlightenment of a Buddha as the ultimative goal and the sutra predicts that all those who hear the Dharma will eventually achieve this goal. The earlier teachings are said to be skilful means to teach beings according to their capacities. The sutra is notable for the (re)appearance of the Buddha Prabhutaratna, who had died several aeons earlier, because it suggests that a Buddha is not inaccessible after his "parinirvāṇa" and also that his life-span is said to be inconceivably long because of the accumulation of merit in past lives. This idea, though not necessarily from this source, forms the basis of the later doctrine of the three bodies ("trikāya"). Later it became associated particularly with the Tien Tai school in China (Tendai in Japan) and the Nichiren schools in Japan. In some East Asian traditions, the Lotus Sūtra has been compiled together with two other sutras which serve as a prologue and epilogue, respectively the "Innumerable Meanings Sutra" and the "Samantabhadra Meditation Sutra". This composite sutra is often called the "Threefold Lotus Sūtra" or "Three-Part Dharma Flower Sutra". The Pure Land teachings were first developed in India, and were very popular in Kashmir and Central Asia, where they may have originated.