03-00 General reference works (handbooks, dictionaries, bibliographies, etc.)
03-01 Instructional exposition (textbooks, tutorial papers, etc.)
03-02 Research exposition (monographs, survey articles)
03-03 Historical (must also be assigned at least one classification number from Section 01)
03-04 Explicit machine computation and programs (not the theory of computation or programming)
03-06 Proceedings, conferences, collections, etc.
03A05 Philosophical and critical {For philosophy of mathematics, see also 00A30}
03Bxx General logic
03Cxx Model theory
03Dxx Computability and recursion theory
03Exx Set theory
03Fxx Proof theory and constructive mathematics
03Gxx Algebraic logic
03Hxx Nonstandard models [See also 03C62]