Anvaya refers to the logical connection of words, as to how different words relate with each other to convey a significant meaning or idea
Literally, Anvaya (Sanskrit: अन्वय) means - positive; affirmative or nexus; but in grammar and logic this word refers to - ‘concordance’ or ‘agreement’, such as the agreement which exists between two things that are present, as between ‘smoke’ and ‘fire’, it is universally known that - “where there is smoke, there is fire”
However, this word is commonly used in Sanskrit grammar and logic along with the word, Vyatireka, which means - agreement in absence between two things, such as absence of ‘smoke’ and ‘fire’ - “where there is no smoke, there is no fire”
Anvaya-vyatireka, is the term used by the Buddhists and Hindu logicians as a dual procedure - to signify ‘separation’ and ‘connection’, and to indicate a type of inference in which hetu (reason) is co-present or is co-absent with sādhya (major term), as the pair of positive and negative instantiations which represent the inductive and the deductive reasoning, both