08XX 


General algebraic systems 

08Bxx 

Varieties [See also 03C05] 


08B05 
Equational logic, Malʹcev (Malʹtsev) conditions 


08B10 
Congruence modularity, congruence distributivity 


08B15 
Lattices of varieties 


08B20 
Free algebras 


08B25 
Products, amalgamated products, and other kinds of limits and colimits [See also 18A30] 


08B26 
Subdirect products and subdirect irreducibility 


08B30 
Injectives, projectives 


08B99 
None of the above, but in this section 