Set colourings of graphs Original Research Article

χ*(G)=infrχ(r)(G)r.By making use of a recent result of L. Lovász we prove that image. In particular, given any image may be arbitrarily close to 2, and given any r, the ratio image may be arbitrarily close to 1, even if H is uniquely colourable. The results disprove a conjecture of D.P. Geller.