Sentence:  In the notation of the proof of Theorem 12 , let us take a look at the special case in which the minimal polynomial for T is a product of first degree polynomials , i.e. , the case in which each * * f is of the <WSD>form</WSD> * * f . 
Meaning of the word marked with <WSD> tags:  a category of things distinguished by some common characteristic or quality