English

Polynomial analogue of Gandhi's fixed point theorem

Computational Complexity 2021-06-18 v7 Logic in Computer Science Logic

Abstract

The problem to be solved in this paper is to construct a general method of proving whether a certain set is p-computable or not. The method is based on a polynomial analogue of the classical Gandhi's fixed point theorem. The classical Gandhi theorem uses the extension of the predicate with the help of the special operator ΓΦ(x)Ω\Gamma^{\Omega^*}_{\Phi(x)} whose smallest fixed point is the Σ\Sigma-set. The work uses a new type of operator - Δ0p\Delta_0^p-operator ΓFP1+,...,FPn+M\Gamma_{F_{P_1^{+}},...,F_{P_n^{+}}}^{\mathfrak{M}}, which extends predicates so that the smallest fixed point remains a p-computable set. Moreover, if in the classical Gandhi's fixed point theorem the special Σ\Sigma-formula Φ(x)\Phi(\overline {x}) is used in the construction of the operator, then in the new operator, instead of a single formula, special generating families of formulas FP1+,...,FPn+F_ {P_1 ^ {+}},...,F_{P_n^{+}}. This work opens up broad prospects for the application of the polynomial analogue of the Gandhi theorem in the construction of new types of terms and formulas, in the construction of new data types and programs of polynomial computational complexity in Turing complete languages.

Keywords

Cite

@article{arxiv.1903.08109,
  title  = {Polynomial analogue of Gandhi's fixed point theorem},
  author = {Andrey Nechesov},
  journal= {arXiv preprint arXiv:1903.08109},
  year   = {2021}
}

Comments

This paper shows how to move from definability to computability: help in creation p-computable programs. This approach based on semantic programs methodology developed by russian mathematicans U.L. Ershov, S.S. Goncharov and D.I. Sviridenko and also based on Gandi's fixed point theorem. Sobolev institute of mathematics. Novosibirsk