Hostname: page-component-6766d58669-6mz5d Total loading time: 0 Render date: 2026-05-15T22:40:37.604Z Has data issue: false hasContentIssue false

AN ALGEBRAIC PROOF OF COMPLETENESS FOR MONADIC FUZZY PREDICATE LOGIC $\mathbf {MMTL}\boldsymbol {\forall }$

Published online by Cambridge University Press:  18 October 2023

JUNTAO WANG
Affiliation:
SCHOOL OF SCIENCE XI’AN SHIYOU UNIVERSITY XI’AN, SHAANXI 710065 CHINA E-mail: wjt@xsyu.edu.cn
HONGWEI WU
Affiliation:
SCHOOL OF SCIENCE XI’AN SHIYOU UNIVERSITY XI’AN, SHAANXI 710065 CHINA E-mail: wuhw@snnu.edu.cn
PENGFEI HE
Affiliation:
SCHOOL OF MATHEMATICS AND STATISTICS SHAANXI NORMAL UNIVERSITY XI’AN, SHAANXI 710119 CHINA E-mail: hepengf1986@126.com
YANHONG SHE*
Affiliation:
SCHOOL OF SCIENCE XI’AN SHIYOU UNIVERSITY XI’AN, SHAANXI 710065 CHINA

Abstract

Monoidal t-norm based logic $\mathbf {MTL}$ is the weakest t-norm based residuated fuzzy logic, which is a $[0,1]$-valued propositional logical system having a t-norm and its residuum as truth function for conjunction and implication. Monadic fuzzy predicate logic $\mathbf {mMTL\forall }$ that consists of the formulas with unary predicates and just one object variable, is the monadic fragment of fuzzy predicate logic $\mathbf {MTL\forall }$, which is indeed the predicate version of monoidal t-norm based logic $\mathbf {MTL}$. The main aim of this paper is to give an algebraic proof of the completeness theorem for monadic fuzzy predicate logic $\mathbf {mMTL\forall }$ and some of its axiomatic extensions. Firstly, we survey the axiomatic system of monadic algebras for t-norm based residuated fuzzy logic and amend some of them, thus showing that the relationships for these monadic algebras completely inherit those for corresponding algebras. Subsequently, using the equivalence between monadic fuzzy predicate logic $\mathbf {mMTL\forall }$ and S5-like fuzzy modal logic $\mathbf {S5(MTL)}$, we prove that the variety of monadic MTL-algebras is actually the equivalent algebraic semantics of the logic $\mathbf {mMTL\forall }$, giving an algebraic proof of the completeness theorem for this logic via functional monadic MTL-algebras. Finally, we further obtain the completeness theorem of some axiomatic extensions for the logic $\mathbf {mMTL\forall }$, and thus give a major application, namely, proving the strong completeness theorem for monadic fuzzy predicate logic based on involutive monoidal t-norm logic $\mathbf {mIMTL\forall }$ via functional representation of finitely subdirectly irreducible monadic IMTL-algebras.

MSC classification

Information

Type
Research Article
Copyright
© The Author(s), 2023. Published by Cambridge University Press on behalf of The Association for Symbolic Logic

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable