13Bxx Ring extensions and related topics

• 13B02 Extension theory
• 13B05 Galois theory (commutative rings)
• 13B10 Morphisms and derivations
• 13B15 Ramification theory
• 13B21 Integral dependence
• 13B22 Integral closure; integrally closed rings, related rings (Japanese, etc.)
• 13B24 Going up; going down; going between
• 13B25 Polynomials over commutative rings
• 13B30 Quotients and localization
• 13B35 Completion, See also {13J10}
• 13B40 Etale extensions and Henselization; Artin approximation, See also {13J15, 14B12}
• 13B99 None of the above but in this section