Propositional Calculus

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 7998 Experts worldwide ranked by ideXlab platform

George Gargov - One of the best experts on this subject based on the ideXlab platform.

Krassimir T Atanassov - One of the best experts on this subject based on the ideXlab platform.

Yang Bingru - One of the best experts on this subject based on the ideXlab platform.

Santocanale Luigi - One of the best experts on this subject based on the ideXlab platform.

  • Fixed-point elimination in the Intuitionistic Propositional Calculus (extended version)
    'Association for Computing Machinery (ACM)', 2019
    Co-Authors: Ghilardi Silvio, Gouveia, Maria Joao, Santocanale Luigi
    Abstract:

    International audienceIt is a consequence of existing literature that least and greatest fixed-points of monotone polynomials on Heyting algebras—that is, the alge- braic models of the Intuitionistic Propositional Calculus—always exist, even when these algebras are not complete as lattices. The reason is that these extremal fixed-points are definable by formulas of the IPC. Consequently, the μ-Calculus based on intuitionistic logic is trivial, every μ-formula being equiv- alent to a fixed-point free formula. We give in this paper an axiomatization of least and greatest fixed-points of formulas, and an algorithm to compute a fixed-point free formula equivalent to a given μ-formula. The axiomatization of the greatest fixed-point is simple. The axiomatization of the least fixed- point is more complex, in particular every monotone formula converges to its least fixed-point by Kleene’s iteration in a finite number of steps, but there is no uniform upper bound on the number of iterations. We extract, out of the algorithm, upper bounds for such n, depending on the size of the formula. For some formulas, we show that these upper bounds are polynomial and optimal

  • Fixed-point elimination in the Intuitionistic Propositional Calculus (extended version)
    2018
    Co-Authors: Ghilardi Silvio, Gouveia, Maria Joao, Santocanale Luigi
    Abstract:

    It is a consequence of existing literature that least and greatest fixed-points of monotone polynomials on Heyting algebras-that is, the alge- braic models of the Intuitionistic Propositional Calculus-always exist, even when these algebras are not complete as lattices. The reason is that these extremal fixed-points are definable by formulas of the IPC. Consequently, the $\mu$-Calculus based on intuitionistic logic is trivial, every $\mu$-formula being equiv- alent to a fixed-point free formula. We give in this paper an axiomatization of least and greatest fixed-points of formulas, and an algorithm to compute a fixed-point free formula equivalent to a given $\mu$-formula. The axiomatization of the greatest fixed-point is simple. The axiomatization of the least fixed- point is more complex, in particular every monotone formula converges to its least fixed-point by Kleene's iteration in a finite number of steps, but there is no uniform upper bound on the number of iterations. We extract, out of the algorithm, upper bounds for such n, depending on the size of the formula. For some formulas, we show that these upper bounds are polynomial and optimal.Comment: extended version of arXiv:1601.0040

  • Fixed-point elimination in the Intuitionistic Propositional Calculus
    HAL CCSD, 2016
    Co-Authors: Ghilardi Silvio, Gouveia, Maria Joao, Santocanale Luigi
    Abstract:

    International audienceIt is a consequence of existing literature that least and greatest fixed-points of monotone polynomials on Heyting algebras—that is, the algebraic models of the Intuitionistic Propositional Calculus—always exist, even when these algebras are not complete as lattices. The reason is that these extremal fixed-points are definable by formulas of the IPC. Consequently, the µ-Calculus based on intuitionistic logic is trivial, every µ-formula being equivalent to a fixed-point free formula. We give in this paper an axiomatization of least and greatest fixed-points of formulas, and an algorithm to compute a fixed-point free formula equivalent to a given µ-formula. The axiomatization of the greatest fixed-point is simple. The axiomatization of the least fixed-point is more complex, in particular every monotone formula converges to its least fixed-point by Kleene's iteration in a finite number of steps, but there is no uniform upper bound on the number of iterations. We extract, out of the algorithm, upper bounds for such n, depending on the size of the formula. For some formulas, we show that these upper bounds are polynomial and optimal

Sanmin Wang - One of the best experts on this subject based on the ideXlab platform.

  • a fuzzy logic for an ordinal sum t norm
    Fuzzy Sets and Systems, 2005
    Co-Authors: Sanmin Wang, Baoshu Wang, Daowu Pei
    Abstract:

    Among the class of residuated fuzzy logics, a few of them have been shown to have standard completeness both for Propositional and predicate Calculus, like Godel, NM and monoidal t-norm-based logic systems. In this paper, a new residuated logic NMG, which aims at capturing the tautologies of a class of ordinal sum t-norms and their residua, is introduced and its standard completeness both for Propositional Calculus and for predicate Calculus are proved.

  • a triangular norm based Propositional fuzzy logic
    Fuzzy Sets and Systems, 2003
    Co-Authors: Sanmin Wang, Baoshu Wang, Guojun Wang
    Abstract:

    In 1997, Wang introduced the formal system L * for a type of fuzzy Propositional Calculus given by a particular t-norm different from the three famous ones (Lukasiewicz, Godel, product). Recently, Pei proved the completeness theorem for L * with respect to W -semantic by developing a theory of algebraic systems. In this paper, we aim to prove it by essentially metamathematical method. Furthermore, we discussed originally the completeness for the schematic extension L n * of L * with respect to W n -semantic.