Abstract
The authors regret that the main theorem of the paper (1.6) is not correct as stated. This is due to a mistake in one of the theorems of [1], that has since been corrected, but added another possible outcome that we need to handle. The present proof of 1.6 requires an additional assumption, and shows the following Theorem If G is a squarefree flat graph, such that no prism of G has a rung of length one, then either G is a complete graph, or G has an even pair. The additional assumption here is that no prism of G has a rung of length one. This assumption can probably be removed, at the cost of making the proof technically much more difficult, but the authors have not been able to do so yet. The authors would like to apologize for any inconvenience caused.
Original language  English (US) 

Pages (fromto)  259260 
Number of pages  2 
Journal  Journal of Combinatorial Theory. Series B 
Volume  133 
DOIs 

State  Published  Nov 2018 
All Science Journal Classification (ASJC) codes
 Theoretical Computer Science
 Discrete Mathematics and Combinatorics
 Computational Theory and Mathematics
Keywords
 Eeven pairs
 Erratum
 Perfect graphs
 Prisms