The succinctness of first-order logic on linear orders

Succinctness is a natural measure for comparing the strength of different logics. Intuitively, a logic L_1 is more succinct than another logic L_2 if all properties that can be expressed in L_2 can be expressed in L_1 by formulas of (approximately) the same size, but some properties can be expressed...

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Main Authors: Martin Grohe, Nicole Schweikardt
Format: Article
Language:English
Published: Logical Methods in Computer Science e.V. 2005-06-01
Series:Logical Methods in Computer Science
Subjects:
Online Access:https://lmcs.episciences.org/2276/pdf
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author Martin Grohe
Nicole Schweikardt
author_facet Martin Grohe
Nicole Schweikardt
author_sort Martin Grohe
collection DOAJ
description Succinctness is a natural measure for comparing the strength of different logics. Intuitively, a logic L_1 is more succinct than another logic L_2 if all properties that can be expressed in L_2 can be expressed in L_1 by formulas of (approximately) the same size, but some properties can be expressed in L_1 by (significantly) smaller formulas. We study the succinctness of logics on linear orders. Our first theorem is concerned with the finite variable fragments of first-order logic. We prove that: (i) Up to a polynomial factor, the 2- and the 3-variable fragments of first-order logic on linear orders have the same succinctness. (ii) The 4-variable fragment is exponentially more succinct than the 3-variable fragment. Our second main result compares the succinctness of first-order logic on linear orders with that of monadic second-order logic. We prove that the fragment of monadic second-order logic that has the same expressiveness as first-order logic on linear orders is non-elementarily more succinct than first-order logic.
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spelling doaj.art-c62bf8d87e9542699d35395c412995d32024-03-07T17:10:13ZengLogical Methods in Computer Science e.V.Logical Methods in Computer Science1860-59742005-06-01Volume 1, Issue 110.2168/LMCS-1(1:6)20052276The succinctness of first-order logic on linear ordersMartin Grohehttps://orcid.org/0000-0002-0292-9142Nicole SchweikardtSuccinctness is a natural measure for comparing the strength of different logics. Intuitively, a logic L_1 is more succinct than another logic L_2 if all properties that can be expressed in L_2 can be expressed in L_1 by formulas of (approximately) the same size, but some properties can be expressed in L_1 by (significantly) smaller formulas. We study the succinctness of logics on linear orders. Our first theorem is concerned with the finite variable fragments of first-order logic. We prove that: (i) Up to a polynomial factor, the 2- and the 3-variable fragments of first-order logic on linear orders have the same succinctness. (ii) The 4-variable fragment is exponentially more succinct than the 3-variable fragment. Our second main result compares the succinctness of first-order logic on linear orders with that of monadic second-order logic. We prove that the fragment of monadic second-order logic that has the same expressiveness as first-order logic on linear orders is non-elementarily more succinct than first-order logic.https://lmcs.episciences.org/2276/pdfcomputer science - logic in computer sciencef.4.1
spellingShingle Martin Grohe
Nicole Schweikardt
The succinctness of first-order logic on linear orders
Logical Methods in Computer Science
computer science - logic in computer science
f.4.1
title The succinctness of first-order logic on linear orders
title_full The succinctness of first-order logic on linear orders
title_fullStr The succinctness of first-order logic on linear orders
title_full_unstemmed The succinctness of first-order logic on linear orders
title_short The succinctness of first-order logic on linear orders
title_sort succinctness of first order logic on linear orders
topic computer science - logic in computer science
f.4.1
url https://lmcs.episciences.org/2276/pdf
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