Research output: Contribution to journal › Article › peer-review
Extensions of unification modulo ACUI. / Baader, Franz; Marantidis, Pavlos; Mottet, Antoine; Okhotin, Alexander.
In: Mathematical Structures in Computer Science, Vol. 30, No. 6, 01.06.2020, p. 597-626.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Extensions of unification modulo ACUI
AU - Baader, Franz
AU - Marantidis, Pavlos
AU - Mottet, Antoine
AU - Okhotin, Alexander
N1 - Funding Information: Supported by DFG Graduiertenkolleg 1763 (QuantLA). ‡ Funding Information: Partially supported by DFG Graduiertenkolleg 1763 (QuantLA). Publisher Copyright: © Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/6/1
Y1 - 2020/6/1
N2 - The theory ACUI of an associative, commutative, and idempotent binary function symbol + with unit 0 was one of the first equational theories for which the complexity of testing solvability of unification problems was investigated in detail. In this paper, we investigate two extensions of ACUI. On one hand, we consider approximate ACUI-unification, where we use appropriate measures to express how close a substitution is to being a unifier. On the other hand, we extend ACUI-unification to ACUIG-unification, that is, unification in equational theories that are obtained from ACUI by adding a finite set G of ground identities. Finally, we combine the two extensions, that is, consider approximate ACUI-unification. For all cases we are able to determine the exact worst-case complexity of the unification problem.
AB - The theory ACUI of an associative, commutative, and idempotent binary function symbol + with unit 0 was one of the first equational theories for which the complexity of testing solvability of unification problems was investigated in detail. In this paper, we investigate two extensions of ACUI. On one hand, we consider approximate ACUI-unification, where we use appropriate measures to express how close a substitution is to being a unifier. On the other hand, we extend ACUI-unification to ACUIG-unification, that is, unification in equational theories that are obtained from ACUI by adding a finite set G of ground identities. Finally, we combine the two extensions, that is, consider approximate ACUI-unification. For all cases we are able to determine the exact worst-case complexity of the unification problem.
KW - ACUI
KW - approximate unification
KW - ground identities
KW - Unification theory
KW - SET
UR - http://www.scopus.com/inward/record.url?scp=85092705427&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/7e31072a-63ed-3ec3-8b5c-52f52088c54b/
U2 - 10.1017/S0960129519000185
DO - 10.1017/S0960129519000185
M3 - Article
AN - SCOPUS:85092705427
VL - 30
SP - 597
EP - 626
JO - Mathematical Structures in Computer Science
JF - Mathematical Structures in Computer Science
SN - 0960-1295
IS - 6
ER -
ID: 70816165