A continuum means comp6lct, connected metric space. A hereditarily unicoherent and arcwise connected continuum is called a dendroid. It follows that it is hereditarily decomposable ([2], (47), p. 239). A hereditarily unicoherent and hereditarily decomposable continuum is said to be a A.-dendroid. Thus, every dendroid is a }.-dendroid and an arcwise connected A.-dendroid is a dendroid. Note that...

A graph G is hereditarily dominated by a class D of connected graphs if each connected induced subgraph of G contains a dominating induced subgraph belonging to D. In this paper we characterize graphs hereditarily dominated by classes of complete bipartite graphs, stars, connected bipartite graphs, and complete k-partite graphs.

Research Article Guram Bezhanishvili, Nick Bezhanishvili, Joel Lucero-Bryan and Jan van Mill S4.3 and hereditarily extremally disconnected spaces Abstract: Themodal logic S4.3 de nes the class of hereditarily extremally disconnected spaces (HED-spaces). We construct a countable HED-subspaceX of the Gleason cover of the real closed unit interval [0, 1] such that S4.3 is the logic ofX.

In [2], Auslander and Smalø introduced and studied extensively preprojective modules and preinjective modules over an artin algebra. We now call a module hereditarily preprojective or hereditarily preinjective if its submodules are all preprojective or its quotient modules are all preinjective, respectively. In [4], Coelho studied Auslander-Reiten components containing only hereditarily preproj...

In 1967 Gurevich [3] published a proof that the class of divisible Axchimedean lat t ice-ordered abelian groups such that the lattice of carriers is an atomic Boolean algebra has a hereditarily undecidable first-order theory. (He essentially showed the reduct of this class to lattices has a hereditarily undecidable first-order theory: on p. 49 of his paper change z ~ u + v to z ~ u v v in the d...

Any hereditarily finite set S can be represented as a finite pointed graph –dubbed membership graph– whose nodes denote elements of the transitive closure of {S} and whose edges model the membership relation. Membership graphs must be hyper-extensional –nodes are pairwise not bisimilar– and bisimilar nodes represent the same hereditarily finite set. It is worth to notice that the removal of eve...

In this paper we answer a question of Wayne Lewis by proving that if X is a one-dimensional, hereditarily indecomposable continuum and if HX(X) is finitely generated, then C(X), the hyperspace of subcontinua of X, has dimension 2. Let C(A) be the hyperspace of subcontinua of the continuum X with the topology determined by the Hausdorff metric. A classical theorem of J. L. Kelley [4] asserts tha...