An example of a Fraïssé class without a Katětov functor

2016/04/01 by Grebík, Jan
#03C50 #18A22 #Category Theory (math.CT) #FOS: Mathematics #Logic (math.LO)

paper · doi:10.48550/arxiv.1604.00358

Abstract

We disprove a conjecture from [W. Kubiś, D. Mašulović, Katětov functors, preprint, http://arxiv.org/abs/1412.1850] by showing the existence of a Fraïssé class C which does not admit a Katětov functor. On the other hand, we show that the automorphism group of the Fraïssé limit of C is universal, as it happens in the presence of a Katětov functor.

Related

• Katetov functors
• Uniform homogeneity
• Ordered structures and large conjugacy classes
• A Fraïssé theory for partial orders of a fixed finite dimension
• Weak Fraisse categories