@InProceedings{cosmellopez_et_al:LIPIcs.MFCS.2017.76, author = {Cosme Ll\'{o}pez, Enric and Pous, Damien}, title = {{K4-free Graphs as a Free Algebra}}, booktitle = {42nd International Symposium on Mathematical Foundations of Computer Science (MFCS 2017)}, pages = {76:1--76:14}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-95977-046-0}, ISSN = {1868-8969}, year = {2017}, volume = {83}, editor = {Larsen, Kim G. and Bodlaender, Hans L. and Raskin, Jean-Francois}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2017.76}, URN = {urn:nbn:de:0030-drops-80883}, doi = {10.4230/LIPIcs.MFCS.2017.76}, annote = {Keywords: Universal Algebra, Graph theory, Axiomatisation, Tree decompositions, Graph minors} }