Vadagrantha is a text comprising statements for the victory of truth. Any text in consonance with the Nyaya-Vaisesika system of philosophy that undertakes to provide a complete explanation of the entire field of worldly experience is termed vadagrantha. It may be establishing any system of philosophy refuting any rival doctrine.
An example would be Khandanakhandakhadya of Sri Harsha, written before the 8th century CE. It is one of the most important treatises of Vedanta. It means destructive criticism. That it can explain neither any factor nor worldly phenomena, nor the ultra-phenomenal consciousness of Brahman, is the thesis upon which the entire work is based. All is inexplicable (anirvaaniyam). In fact, so thorough is the inexplicability propounded that the author also is denying the reality of the world as a means of cognition; and yet, it is upon Vedic texts that he bases his notion of non-duality. What the author has adopted to submit to a critical investigation are the definitions logicians give the main categories and cognitional activities. This leads us to the conclusion that all those definitions are bound to suffer from inner contradictions and become untenable.
Other examples would be Vedanta Desika’s Satadushani, a treatise in Visishtadvaita philosophy. Appayya Dikshita wrote Vedantadipa to refute vadas in Satadusani and re-established Advaita philosophy. Later, Sri Candamarutam Doddacharya wrote Candamarutam, an explanatory commentary to Satadushani with panca vijayas (like Advaita Vijaya, Brahmavidya Vijaya, Parasarya Vijaya) and re-established the tenets of Satadusani according to the Visishtadvaita philosophy.