What is "prasthanatrayi"

Prasthanatrayi (, IAST: ), literally, three sources, refers to the three canonical texts of Hindu philosophy, especially of the Vedanta schools. It consists of:

1. The Upanishads, known as Upadesha prasthana (injunctive texts), and the Śruti prasthāna (the starting point of revelation)
2. The Brahma Sutras, known as Nyaya prasthana or Yukti prasthana (logical text)
3. The Bhagavad Gita, known as Sadhana prasthana (practical text), and the Smriti prasthāna (the starting point of remembered tradition)

The Upanishads consist of twelve or thirteen major texts, with a total of 108 texts. The is part of the .The (also known as the ), systematize the doctrines taught in the Upanishads and the .

All the founders of the three major schools of Vedanta, viz, Adi Shankara, Ramanujacharya, Nimbarkacharya and Madhva wrote (commentaries) on these texts.