Sentence:  A function g such that * * f , i.e. , * * f , must be a polynomial <WSD>function</WSD> of degree * * f or less : * * f . 
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)