13XX 


Commutative algebra 

13Bxx 

Ring extensions and related topics 


13B02 
Extension theory 


13B05 
Galois theory 


13B10 
Morphisms 


13B21 
Integral dependence; going up, going down 


13B22 
Integral closure of rings and ideals [See also 13A35]; integrally closed rings, related rings (Japanese, etc.) 


13B25 
Polynomials over commutative rings [See also 11C08, 11T06, 13F20, 13M10] 


13B30 
Rings of fractions and localization [See also 16S85] 


13B35 
Completion [See also 13J10] 


13B40 
Étale and flat extensions; Henselization; Artin approximation [See also 13J15, 14B12, 14B25] 


13B99 
None of the above, but in this section 