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Some problems not definable using structure homomorphisms

Madelaine, F.R.; Stewart, I.A.


F.R. Madelaine


We exhibit some problems definable in Feder and Vardi's logic MMSNP that are not in the class CSP of constraint satisfaction problems. Whilst some of these problems have previously been shown to be in MMSNP (that is, definable in MMSNP) but not in CSP, existing proofs are probabilistic in nature. We provide explicit combinatorial constructions to prove that these problems are not in CSP and we use these constructions to exhibit yet more problems in MMSNP that are not in CSP.


Madelaine, F., & Stewart, I. (2003). Some problems not definable using structure homomorphisms. Ars combinatoria, 67, 153-159

Journal Article Type Article
Publication Date Apr 1, 2003
Deposit Date Jun 29, 2009
Journal Ars combinatoria.
Print ISSN 0381-7032
Publisher Charles Babbage Research Centre
Peer Reviewed Peer Reviewed
Volume 67
Pages 153-159
Keywords Constraint satisfaction, CSP, MMSNP.
Publisher URL