Tameness in least fixed-point logic and mccolm’s conjecture
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Tameness in least fixed-point logic and mccolm’s conjecture. / Bhaskar, Siddharth; Kruckman, Alex.
In: Logical Methods in Computer Science, Vol. 17, No. 1, 2, 2021, p. 2:1-2:16.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Tameness in least fixed-point logic and mccolm’s conjecture
AU - Bhaskar, Siddharth
AU - Kruckman, Alex
N1 - Publisher Copyright: © Siddharth Bhaskar and Alex Kruckman.
PY - 2021
Y1 - 2021
N2 - We investigate four model-theoretic tameness properties in the context of least fixed-point logic over a family of finite structures. We find that each of these properties depends only on the elementary (i.e., first-order) limit theory, and we completely determine the valid entailments among them. In contrast to the context of first-order logic on arbitrary structures, the order property and independence property are equivalent in this setting. McColm conjectured that least fixed-point definability collapses to first-order definability exactly when proficiency fails. McColm’s conjecture is known to be false in general. However, we show that McColm’s conjecture is true for any family of finite structures whose limit theory is model-theoretically tame.
AB - We investigate four model-theoretic tameness properties in the context of least fixed-point logic over a family of finite structures. We find that each of these properties depends only on the elementary (i.e., first-order) limit theory, and we completely determine the valid entailments among them. In contrast to the context of first-order logic on arbitrary structures, the order property and independence property are equivalent in this setting. McColm conjectured that least fixed-point definability collapses to first-order definability exactly when proficiency fails. McColm’s conjecture is known to be false in general. However, we show that McColm’s conjecture is true for any family of finite structures whose limit theory is model-theoretically tame.
KW - Finite model theory
KW - Inductive definability
KW - Least fixed-point logic
KW - Model-theoretic dividing lines
UR - http://www.scopus.com/inward/record.url?scp=85101617873&partnerID=8YFLogxK
U2 - 10.23638/LMCS-17(1:2)2021
DO - 10.23638/LMCS-17(1:2)2021
M3 - Journal article
AN - SCOPUS:85101617873
VL - 17
SP - 2:1-2:16
JO - Logical Methods in Computer Science
JF - Logical Methods in Computer Science
SN - 1860-5974
IS - 1
M1 - 2
ER -
ID: 269503322