Funcions booleanes: caracterització dels nivells de la jerarquia booleana

Abstract

We study two hierarchies defined beetwen NP and ¿p2: The K-Boolean Hierarchy, when K=NP, (Wechsung, Wagner (1985)), and the Boolean Hierarchy (Cai, Hemachandra (1986)). Every level of these two hierarchies is caracterized by boolean functions in the first case and by operators over sets in the second case. Using these caracterizations, we prove the interrelations beetwen the levels of the hierarchies.