Sparse sets, lowness, and highness
Tipo de documentoArtículo
Fecha de publicación1986-08
Condiciones de accesoAcceso abierto
We develop the notions of “generalized lowness” for sets in PH (the union of the polynomial-time hierarchy) and of “generalized highness” for arbitrary sets. Also, we develop the notions of “extended lowness” and “extended highness” for arbitrary sets. These notions extend the decomposition of NP into low sets and high sets developed by Schöning  and studied by Ko and Schöning . We show that either every sparse set in PH is generalized high or no sparse set in PH is generalized high. Further, either every sparse set is extended high or no sparse set is extended high. In both situations, the former case corresponds to the polynomial-time hierarchy having only finitely many levels while the latter case corresponds to the polynomial-time hierarchy extending infinitely many levels.
CitaciónBalcazar, J. L., Book, R., Schoening, U. Sparse sets, lowness, and highness. "SIAM journal on computing", Agost 1986, vol. 15, núm. 1, p. 739-747.
Versión del editorhttp://epubs.siam.org/doi/abs/10.1137/0215053