On P versus NP CO-NP for decision trees and read-once branching programs

The OR-SAT problem asks, given Boolean formulae @f"1,...,@f"m each of size at most n, whether at least one of the @f"i's is satisfiable. We show that there is no reduction from OR-SAT to any set A where the length of the output is bounded by a ...

We investigate the relationship between probabilistic and nondeterministic complexity classes PP, BPP, NP and coNP with respect to ordered read-once branching programs (OBDDs). We exhibit two explicit Boolean functions q_n; R_n such that: (1) q_n : {0,1}ⁿ →...

We study the shrinking and separation properties (two notions well-known in descriptive set theory) for NP and coNP and show that under reasonable complexity-theoretic assumptions, both properties do not hold for NP and the shrinking property does not ...