Let U = (U,L) be a universal binary countable homogeneous structure and n âˆˆ Ï‰. We determine the equivalence relation C(n)(U) on [U ] with the smallest number of equivalence classes r so that each oneâ€¦ (More)

We show that for each positive integer n there is a finite list of equivalence relations on [Q]n with the property that for every other equivalence relation E on [Q]n there is X âŠ† Q of order typeâ€¦ (More)

We show that for every positive integer d, every downwards closed subtree T of d without terminal nodes and every finite weakly embedded subtree A of T there is a finite list of equivalence relationsâ€¦ (More)