Sentence:  The extent to which the public limit price is raised by a given increase in the basic wage rate is itself a <WSD>function</WSD> of three things : the passage of time , the level of GNP , and the size of the wage increase . 
Meaning of the word marked with <WSD> tags:  (mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)