Finite-Rank Operators are Compact Analysis Decay Of Fourier Coefficients Under Differentiability Harmonic Analysis Vector Space Structure of Compact Operators Analysis ML Inequality for Contour Integrals Complex Analysis General Leibniz Rule Differential Calculus Heine–Borel Theorem Topology Cotlar–Stein Lemma Analysis Eigenvalues of Non-Symmetric Elliptic Operators Partial Differential Equations Analysis Area