A note on unification type zero
type: Item
instance of: scholarly article
title: A note on unification type zero
zbMATH Open document ID: 0636.68030
DOI: 10.1016/0020-0190(88)90098-1
author: Franz Baader
published in: Information Processing Letters
publication date: 1988-01-01T00:00:00Z
review text: An equational theory E is of unification type zero if there exist terms s, t for which there is no minimal complete set of E-unifiers of s, t. The existence of such a theory E was conjectured by Plotkin in 1972. The first example of a theory of this type was constructed by Fages and Huet in 1983. The present paper shows that the theory of idempotent semigroups is of unification type zero. This yields an example of a theory of type zero which is more natural than the example given by Fages and Huet.
Mathematics Subject Classification ID: 68Q42
Mathematics Subject Classification ID: 03B35
Mathematics Subject Classification ID: 20M07
zbMATH DE Number: 4037183
zbMATH Keywords: term rewriting systems
zbMATH Keywords: equational theory
zbMATH Keywords: unification
zbMATH Keywords: idempotent semigroups
Wikidata QID: Q57383758
MaRDI profile type: Publication
full work available at URL: 0020-0190(88)90098-1
OpenAlex ID: W2030476257
cites work: The theory of idempotent semigroups is of unification type zero
cites work: Unification in varieties of idempotent semigroups
cites work: Q3779785
cites work: Q3335752
cites work: Complete sets of unifiers and matchers in equational theories
cites work: Q5678447
cites work: Unification under associativity and idempotence is of type nullary
DBLP publication ID: journals/ipl/Baader88
description: scientific article; zbMATH DE number 4037183