residue theorem
the theorem that complex contour integrals are simply the sums of residues of singularities contained within the contour
en-GB/ˈɹɛsɪˌdjuː ˈθɪəɹəm/
en-US/ˈɹɛzəˌdu ˈθɪɹəm/
the theorem that complex contour integrals are simply the sums of residues of singularities contained within the contour