On the decidability of monadic first order logic in sequent calculus

In this article, a syntactical proof of decidability ofmonadic first-order logic (and of its completeness for finite models) is given. Theproof is obtained  by adapting to the case of monadic logic, the proof given byKetonen/Schütte for first-order logic completeness (method of “construction of ther...

Full description

Bibliographic Details
Main Author: Jean-Baptiste Joinet
Format: Article
Language:Portuguese
Published: Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) 2016-12-01
Series:O Que Nos Faz Pensar
Online Access:http://www.oquenosfazpensar.fil.puc-rio.br/index.php/oqnfp/article/view/515
_version_ 1811334258925502464
author Jean-Baptiste Joinet
author_facet Jean-Baptiste Joinet
author_sort Jean-Baptiste Joinet
collection DOAJ
description In this article, a syntactical proof of decidability ofmonadic first-order logic (and of its completeness for finite models) is given. Theproof is obtained  by adapting to the case of monadic logic, the proof given byKetonen/Schütte for first-order logic completeness (method of “construction of therefutation tree”, which actually describes, for the propositional fragment, adecision algorithm).  In the general case (i.e. not restricted to monadic logic), the treatment of existential quantifiers imposes an enumeration of all the terms ofthe language, treatment that prevents the algorithm’s termination, and thus the decision. In the monadic case, however, any formula can be put in a specificcanonical form, a result due to H. Behmann (1922), canonical form which implies thatonly a bounded set of terms have to be taken in consideration. The treatment of existential quantifiers can thus be done with a finite number of terms.Decidability (and completeness for finite models) of the monadic case follows. --- Original in French.
first_indexed 2024-04-13T17:06:03Z
format Article
id doaj.art-6bfe2df5e6474386b2d7a1808eb16ca8
institution Directory Open Access Journal
issn 0104-6675
language Portuguese
last_indexed 2024-04-13T17:06:03Z
publishDate 2016-12-01
publisher Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio)
record_format Article
series O Que Nos Faz Pensar
spelling doaj.art-6bfe2df5e6474386b2d7a1808eb16ca82022-12-22T02:38:28ZporPontifícia Universidade Católica do Rio de Janeiro (PUC-Rio)O Que Nos Faz Pensar0104-66752016-12-0125395569515On the decidability of monadic first order logic in sequent calculusJean-Baptiste Joinet0Université Jean Moulin, Lyon 3In this article, a syntactical proof of decidability ofmonadic first-order logic (and of its completeness for finite models) is given. Theproof is obtained  by adapting to the case of monadic logic, the proof given byKetonen/Schütte for first-order logic completeness (method of “construction of therefutation tree”, which actually describes, for the propositional fragment, adecision algorithm).  In the general case (i.e. not restricted to monadic logic), the treatment of existential quantifiers imposes an enumeration of all the terms ofthe language, treatment that prevents the algorithm’s termination, and thus the decision. In the monadic case, however, any formula can be put in a specificcanonical form, a result due to H. Behmann (1922), canonical form which implies thatonly a bounded set of terms have to be taken in consideration. The treatment of existential quantifiers can thus be done with a finite number of terms.Decidability (and completeness for finite models) of the monadic case follows. --- Original in French.http://www.oquenosfazpensar.fil.puc-rio.br/index.php/oqnfp/article/view/515
spellingShingle Jean-Baptiste Joinet
On the decidability of monadic first order logic in sequent calculus
O Que Nos Faz Pensar
title On the decidability of monadic first order logic in sequent calculus
title_full On the decidability of monadic first order logic in sequent calculus
title_fullStr On the decidability of monadic first order logic in sequent calculus
title_full_unstemmed On the decidability of monadic first order logic in sequent calculus
title_short On the decidability of monadic first order logic in sequent calculus
title_sort on the decidability of monadic first order logic in sequent calculus
url http://www.oquenosfazpensar.fil.puc-rio.br/index.php/oqnfp/article/view/515
work_keys_str_mv AT jeanbaptistejoinet onthedecidabilityofmonadicfirstorderlogicinsequentcalculus