English

Hard 3-CNF-SAT problems are in $P$ -- A first step in proving $NP=P$

Computational Complexity 2020-01-06 v1

Abstract

The relationship between the complexity classes PP and NPNP is an unsolved question in the field of theoretical computer science. In the first part of this paper, a lattice framework is proposed to handle the 3-CNF-SAT problems, known to be in NPNP. In the second section, we define a multi-linear descriptor function Hφ{\cal H}_\varphi for any 3-CNF-SAT problem φ\varphi of size nn, in the sense that Hφ:{0,1}n{0,1}n{\cal H}_\varphi : \{0,1\}^n \rightarrow \{0,1\}^n is such that Im  HφIm \; {\cal H}_\varphi is the set of all the solutions of φ\varphi. A new merge operation HφHψ{\cal H}_\varphi \bigwedge {\cal H}_{\psi} is defined, where ψ\psi is a single 3-CNF clause. Given Hφ{\cal H}_\varphi [but this can be of exponential complexity], the complexity needed for the computation of Im  HφIm \; {\cal H}_\varphi, the set of all solutions, is shown to be polynomial for hard 3-CNF-SAT problems, i.e. the one with few (2k\leq 2^k) or no solutions. The third part uses the relation between Hφ{\cal H}_\varphi and the indicator function 1Sφ\mathbb{1}_{{\cal S}_\varphi} for the set of solutions, to develop a greedy polynomial algorithm to solve hard 3-CNF-SAT problems.

Keywords

Cite

@article{arxiv.2001.00760,
  title  = {Hard 3-CNF-SAT problems are in $P$ -- A first step in proving $NP=P$},
  author = {Marcel Rémon and Johan Barthélemy},
  journal= {arXiv preprint arXiv:2001.00760},
  year   = {2020}
}

Comments

First draft, comments and suggestion are welcome

R2 v1 2026-06-23T13:02:06.845Z