The polynomial hierarchy is a grading of problems by difficulty, including P, NP and coNP as the best known classes. The promise polynomial hierarchy is similar, but extended to include promise problems. It turns out that the promise polynomial hierarchy is considerably simpler to work with, and many open questions about the polynomial hierarchy can be resolved in the promise polynomial hierarc...

Termination of loops can be inferred from the existence of linear ranking functions. We already know that the existence of these functions is PTIME decidable for simple rational loops. Since very recently, we know that the problem is coNP-complete for simple integer loops. We continue along this path by investigating programs dealing with floating-point computations. First, we show that the pro...

In this note we show how any formula δ with a proof of super-polynomial size in M→ has a poly-sized proof in K→ . This fact entails that any propositional classical tautology has short proofs, i.e., NP=CoNP. 1 Every classical tautology has short proofs This article reports the results on the investigation on the existence of short proofs for every Classical Propositional Logic tautology. Firstl...

This paper analyzes to what extent it is possible to efficiently reduce the number of clauses in NP-hard satisfiability problems, without changing the answer. Upper and lower bounds are established using the concept of kernelization. Existing results show that if NP 6⊆ coNP/poly, no efficient preprocessing algorithm can reduce n-variable instances of cnf-sat with d literals per clause, to equiv...

membrane permeability and p-glycoprotein (p-gp) efflux system are regulating factors in the drug brain penetration. recently, some drug delivery systems have been developed to overcome these limitations. in this study, metoclopramid has been encapsulated in plga nanoparticles using the emulsification/solvent evaporation technique for in vitro evaluation of the effect of plga nanoparticles on bb...