08Axx Algebraic structures

08A02  Relational systems, laws of composition
08A05  Structure theory
08A30  Subalgebras, congruence relations
08A35  Automorphisms, endomorphisms
08A40  Operations, polynomials, primal algebras
08A45  Equational compactness
08A50  Word problems, See also {03D40,  06B25,  20F10,  68R15}
08A55  Partial algebras
08A60  Unary algebras
08A62  Finitary algebras
08A65  Infinitary algebras
08A70  Applications of universal algebra in computer science
08A99  None of the above but in this section