03D20 Recursive functions and relations, subrecursive hierarchies

03D25 Recursively (computably) enumerable sets and degrees

03D32 Algorithmic randomness and dimension [See also <a href="#code:68Q30">68Q30</a>]

03D35 Undecidability and degrees of sets of sentences

03D45 Theory of numerations, effectively presented structures [See also <a href="#code:03C57">03C57</a>; for intuitionistic and similar approaches see <a href="#code:03F55">03F55</a>]

03D50 Recursive equivalence types of sets and structures, isols

03D60 Computability and recursion theory on ordinals, admissible sets, etc.

03D65 Higher-type and set recursion theory

03D75 Abstract and axiomatic computability and recursion theory

03D78 Computation over the reals {For constructive aspects, see <a href="#code:03F60">03F60</a>}

03D80 Applications of computability and recursion theory

03D99 None of the above, but in this section

03E04 Ordered sets and their cofinalities; pcf theory

03E15 Descriptive set theory [See also <a href="#code:28A05">28A05</a>, <a href="#code:54H05">54H05</a>]

03E17 Cardinal characteristics of the continuum

03E20 Other classical set theory (including functions, relations, and set algebra)

03E25 Axiom of choice and related propositions

03E30 Axiomatics of classical set theory and its fragments

03E35 Consistency and independence results

03E40 Other aspects of forcing and Boolean-valued models

03E45 Inner models, including constructibility, ordinal definability, and core models

03E47 Other notions of set-theoretic definability

03E50 Continuum hypothesis and Martin's axiom [See also  03E57]

03E57 Generic absoluteness and forcing axioms [See also  03E50]

03E70 Nonclassical and second-order set theories

03E99 None of the above, but in this section

03Fxx Proof theory and constructive mathematics

03F05 Cut-elimination and normal-form theorems

03F15 Recursive ordinals and ordinal notations

03F25 Relative consistency and interpretations

03F30 First-order arithmetic and fragments

03F35 Second- and higher-order arithmetic and fragments [See also <a href="#code:03B30">03B30</a>]