Propositional theories are strongly equivalent to logic programs

This paper presents a property of propositional theories un der the answer sets semantics (called Equilibrium Logic for this general syntax): any theory can always be reexpress ed as a strongly equivalent disjunctive logic program, possib ly with negation in the head. We provide two different proofs for this result: one involvin g a syntactic transformation, and one that constructs a program starting from the counterm odels of the theory in the intermediate logic of here-and-there.