Sentence:  If * * f are the projections associated with the primary decomposition of T , then each * * f is a polynomial in T , and accordingly if a linear operator U commutes with T then U commutes with each of the * * f <WSD>i.e.</WSD> , each subspace * * f is invariant under U . 
Meaning of the word marked with <WSD> tags:  that is to say; in other words