The purpose of AIT (Analytical Indicant theory) is a very simple one - it is to propose that the ‘BE’ word and the copula 'IS' is not a verb, but a marker which indicates and  establishes the current state of an object or indicates a result of some kind basically by its syntactic position in the sentence.  In a SOV language like English, this usually means: *that which follows is the existential state of the subject. Hence in the sentence: *The apple is red* the copula *IS* indicated that the predicate word *red* is the present existential state of the apple.

The copula 'is' and the rest of the BE cluster: 'was, were, is, am, are, being, ’ and ‘will be'etc., play a vital role in the enabling of utterances as ontological syntactic markers and furnish a mechanism that introduces, allows, and processes this ontological delineative colloquy. It is the firm opinion of AIT thinkers that the copula in all world languages is not and never was designedly or developmentally copuletic in its function. The name ‘copula’ is a medieval misnomer.  Jud Evans - 20 June 2007