Explanation:

Nirgrantha is a term found in Pali Buddhist literature meaning "Freed from all ties." Devotees, naked mendicants, are free from all ties, wander naked, and cover themselves with ashes. Mahavira (Mahavira), the most recent tirthankara of Jainism and a contemporary of Gautama Buddha, called Jñati after his family, is referred to as the Nirgrantha-jñatiputra in the Pali tipitaka.
Digambara monk (also muni, sadhu) is a monk in the Digambara tradition of Jainism, and as such an occupant of the highest limb of the four-fold sangha. They are also called nirgrantha which means "one without any bonds".

The Fourteen Purvas, translated as ancient or prior knowledge, are a large body of Jain scriptures that was preached by all Tirthankaras (omniscient teachers) of Jainism encompassing the entire gamut of knowledge available in this universe.

Angas and Upangas are also Jaina Texts.(Canonical Texts)
Angas (also known as agamas) are 45 sacred texts of Jainism based on the discourse of the tirthankara. The discourse delivered in a samavasarana (divine preaching hall) is called Shrut Jnana and comprises eleven angas and fourteen purvas. The discourse is recorded by Ganadharas (chief disciples), and is composed of twelve angas. It is generally represented by a tree with twelve branches. This forms the basis of the Jaina Agamas or canons. These are believed to have originated from Rishabhanatha, the first tirthankara.
Based on these Angas, the seers also compiled 12 auxiliary works that came to be known as Upangas. These 24 compilations should have been completed by the time of Jambuswami who was the second successor of the reli gious order set up by Lord Mahavir and also was the last omniscient of the current time cycle.