Finite algebras of relations are representable on finite sets
Hajnal Andréka, Ian Hodkinson, Istvàn Németi · Journal of Symbolic Logic · 1999
Abstract Using a combinatorial theorem of Herwig on extending partial isomorphisms of relational structures, we give a simple proof that certain classes of algebras, including Crs, polyadic Crs, and WA, have the ‘finite base property’ and have decidable universal theories, and that any finite algebra in each class is representable on a finite set.