Finite Sholander trees, trees, and their betweenness

We provide a proof of Sholander's claim [M. Sholander, Trees, lattices, order, and betweenness, Proceedings of the American Mathematical Society 3 (1952) 369-381] concerning the representability of collections of so-called segments by trees, which yields a characterization of the interval function of a tree. Furthermore, we streamline Burigana's characterization [L. Burigana, Tree representations of betweenness relations defined by intersection and inclusion, Mathematics and Social Sciences 185 (2009) 5-36] of tree betweenness and provide a relatively short proof.

► Finite Sholander trees are trees in the usual sense. ► This yields a new axiomatic characterization of the interval function of a tree. ► We give a short proof of Burigana's axiomatic characterization of tree betweenness.