35Axx General theory

35A05  General existence and uniqueness theorems
35A07  Local existence and uniqueness theorems, See also {35H05,
               35Sxx}
35A08  Fundamental solutions
35A10  Cauchy-Kovalevskaya theorems
35A15  Variational methods
35A20  Analytic methods, singularities
35A22  Transform methods (e.g. integral transforms)
35A25  Other special methods
35A27  Microlocal methods; methods of sheaf theory and homological
               algebra in PDE, See also {32C38, 58G07}
35A30  Geometric theory, characteristics, transformations, See
               also {58G35, 58G37}
35A35  Theoretical approximation to solutions
35A40  Numerical approximation to solutions, {For numerical
               analysis, See 65Mxx, 65Nxx, 65P05}
35A99  None of the above but in this section