41-XX Approximations and expansions

• 41-00 General reference works (handbooks, dictionaries, bibliographies, etc.)
• 41-01 Instructional exposition (textbooks, tutorial papers, etc.)
• 41-02 Research exposition (monographs, survey articles)
• 41-03 Historical (must be assigned at least one classification number from Section 01)
• 41-04 Explicit machine computation and programs (not the theory of computation or programming)
• 41-06 Proceedings, conferences, collections, etc.
• 41A05 Interpolation [See also 42A15 and 65D05]
• 41A10 Approximation by polynomials {For approximation by trigonometric polynomials, see 42A10}
• 41A15 Spline approximation
• 41A17 Inequalities in approximation (Bernstein-, Jackson-, Nikol\cprime ski\u\i-type inequalities)
• 41A20 Approximation by rational functions
• 41A21 Pad\'e approximation
• 41A25 Rate of convergence, degree of approximation
• 41A27 Inverse theorems
• 41A28 Simultaneous approximation
• 41A29 Approximation with constraints
• 41A30 Approximation by other special function classes
• 41A35 Approximation by operators (in particular, by integral operators)
• 41A36 Approximation by positive operators
• 41A40 Saturation
• 41A44 Best constants
• 41A45 Approximation by arbitrary linear expressions
• 41A46 Approximation by arbitrary nonlinear expressions; widths and entropy
• 41A50 Best approximation, Chebyshev systems
• 41A52 Uniqueness of best approximation
• 41A55 Approximate quadratures
• 41A58 Series expansions (e.g.\ Taylor, Lidstone series, but not Fourier series)
• 41A60 Asymptotic approximations, asymptotic expansions (steepest descent, etc.) [See also 30E15]
• 41A63 Multidimensional problems (should also be assigned at least one other classification number in this section)
• 41A65 Abstract approximation theory (approximation in normed linear spaces and other abstract spaces)
• 41A80 Remainders in approximation formulas
• 41A99 Miscellaneous topics