ABSTRACT
We refer to [28] for preliminaries on topological spaces. Let B be a finite algebra. The alter ago of B is a structured topological space B, where the topology is the discrete topology on B and the additional structure consists of a system of (possibly infinitely many) operations, partial operations and relations on B each of which must be a subuniverse of the appropriate finite direct power of the algebra B. We write A € SP (B ) if A is isomorphic to a subalgebra of a direct power of B. Then the set H o m ( i 4 , B ) of all homomorphisms from A to B is a topologically closed subuniverse of BA. The structured topological space D(j4) of A is called the dual of A with respect to B.
