 Moreover, the set "V" can be safely ignored since "e" is zero on it and therefore makes no contribution to the integral.The projection "e"("T") is called the spectral projection of "T" at "K" and is denoted by "P"("K";"T").Thus every subset "K" of "σ"("T") that is both open and closed in the subspace topology has an associated spectral projection given by

where Γ is a contour that encloses "K" but no other points of σ("T").