18XX 


Category theory; homological algebra {For commutative rings see 13Dxx, for associative rings 16Exx, for groups 20Jxx, for topological groups and related structures 57Txx; see also 55Nxx and 55Uxx for algebraic topology} 

18Gxx 

Homological algebra [See also 13Dxx, 16Exx, 20Jxx, 55Nxx, 55Uxx, 57Txx] 


18G05 
Projectives and injectives [See also 13C10, 13C11, 16D40, 16D50] 


18G10 
Resolutions; derived functors [See also 13D02, 16E05, 18E25] 


18G15 
Ext and Tor, generalizations, Künneth formula [See also 55U25] 


18G20 
Homological dimension [See also 13D05, 16E10] 


18G25 
Relative homological algebra, projective classes 


18G30 
Simplicial sets, simplicial objects (in a category) [See also 55U10] 


18G35 
Chain complexes [See also 18E30, 55U15] 


18G40 
Spectral sequences, hypercohomology [See also 55Txx] 


18G50 
Nonabelian homological algebra 


18G55 
Homotopical algebra 


18G60 
Other (co)homology theories [See also 19D55, 46L80, 58J20, 58J22] 


18G99 
None of the above, but in this section 