Siggers, Mark Reflexive graphs with near unanimity but no semilattice polymorphisms. (English) Zbl 1401.05253 Electron. J. Comb. 25, No. 4, Research Paper P4.2, 13 p. (2018). MSC: 05C75 08B05 06A07 PDFBibTeX XMLCite \textit{M. Siggers}, Electron. J. Comb. 25, No. 4, Research Paper P4.2, 13 p. (2018; Zbl 1401.05253) Full Text: Link
Larose, Benoit Algebra and the complexity of digraph CSPs: a survey. (English) Zbl 1482.68166 Krokhin, Andrei (ed.) et al., The constraint satisfaction problem: complexity and approximability, Dagstuhl seminar 15301, July 2015. Wadern: Schloss Dagstuhl – Leibniz Zentrum für Informatik. Dagstuhl Follow-Ups 7, 267-285 (2017). MSC: 68R07 05C20 08A70 68Q25 68R10 PDFBibTeX XMLCite \textit{B. Larose}, Dagstuhl Follow-Ups 7, 267--285 (2017; Zbl 1482.68166) Full Text: DOI
Hell, Pavol; Siggers, Mark Semilattice polymorphisms and chordal graphs. (English) Zbl 1284.05125 Eur. J. Comb. 36, 694-706 (2014). MSC: 05C25 PDFBibTeX XMLCite \textit{P. Hell} and \textit{M. Siggers}, Eur. J. Comb. 36, 694--706 (2014; Zbl 1284.05125) Full Text: DOI