  Since language does not consist solely of unarticulated sentences or names, there are expressions of other categories, which combine in a rule-governed way with one another to produce further expressions, ultimately sentences. In the regimented environment of Leśniewski’s logical languages this always takes place in the following way: a combining expression, which we may call a functor, precedes a left parenthesis of some kind, which is then followed by a sequence of one or more argument expressions, followed by a right parenthesis symmetric to the other one, which terminates the complex. The general schema is then