Pānini's Replacement Technique and the Active Finite Verb
Barend A. van Nooten · Language · 1967
That section of Pāṇini's grammar which deals with Sanskrit morphology has an underlying principle which in this paper is illustrated by the theory of the active finite verb. The rules that govern the formation of the verb from its elements are stated in terms of replacements. In theory, these are valid throughout the grammar, but by the grammar's design the replacement rules are only effectively operative in specific environments. The rules, their scope, and their occasional failures are given in detail.