The Lexical Integrity Hypothesis (LIH) or Lexical Integrity Principle is a hypothesis in linguistics which states that syntactic transformations do not apply to subparts of words. It functions as a constraint on transformational grammar. Words are analogous to atoms in that, from the point of view of syntax, words do not have any internal structure and are impenetrable by syntactic operations. The ideas of this theory are complicated when considering the hierarchical levels of word formation and the broad variation in defining what constitutes a word, and when words are inserted. Different theories have been proposed by linguists to further refine this theory in order to account for cross-linguistic challenges to the Lexical Integrity Hypothesis. Two linguists, Joan Bresnan of Stanford University and Sam Mchombo of the University of California, Berkeley, maintain the idea of words as unanalyzable units; re-evaluate this theory using evidence from Bantu to resolve clitics' apparent violations of the Lexical Integrity Hypothesis. They concluded that clitics and their prosodic word hosts are separate entities, thus stipulating that the hypothesis does not govern the prosodic word, but rather, the morphosyntactic word. This hypothesis is incompatible with endoclitics, claimed to exist e.g. in the Udi language. It is also incompatible with Arrernte, a language spoken in the Alice Springs area of Australia. Arrernte reportedly has 'initial separation' where "the first two, or rarely three syllables of a verb can optionally be separated from the remainder of the verb. Intervening material seems to be limited to particles, clitics, pronouns, and simple NPs." (Henderson 2002) History The Lexical Integrity Hypothesis is a subset of the Lexicalist hypothesis, which states that morphology and syntax do not interact, with the result (among others) that some syntactic operations cannot access word-internal structures. This theory appears to have no single source from which it originates. Despite being widely referred to and debated in linguistics, there is no single attributable source for the Lexical Integrity Hypothesis, nor does there seem to be any single definition, which potentially poses problems for this theory's falsifiability. The hypothesis seems to come about from the consensus that there is a phenomenon that generally and cross-linguistically prevents or limits the interaction between syntax and morphology. Though not referred to by name, the earliest theoretical beginnings of the Lexical Integrity Hypothesis seems to be from , while linguist Andrew Carstairs-McCarthy interestingly attributes it to , even though Bresnan and Mchombo themselves