![Loading...](https://link.springer.com/static/c4a417b97a76cc2980e3c25e2271af3129e08bbe/images/pdf-preview/spacer.gif)
-
Article
More results in polychromatic Ramsey theory
We study polychromatic Ramsey theory with a focus on colourings of [ω 2]2. We show that in the absence of GCH there is a wide range of possibilities. In particular each of the following is consist...
-
Article
Poset algebras over well quasi-ordered posets
A new class of partial order-types, class \({\mathcal{G}}^{+}_{bqo}\) is defined and investigated here. A poset P is ...
-
Article
Infinite games on finite sets
We study a family of infinite games with imperfect information introduced by B. Model for two players that alternately remove and add points to a finite set. We investigate the existence of imperfect informati...
-
Article
On Jakovlev spaces
A topological spaceX is called weakly first countable, if for every pointx there is a countable family {C n x |n ∈ω} such thatx ∈C ...
-
Article
On Poset Boolean Algebras
Let (P,≤) be a partially ordered set. The poset Boolean algebra of P, denoted F(P), is defined as follows: The set of generators of F(P) is {x p : p∈P}, and the...
-
Article
On a superatomic Boolean algebra which is not generated by a well-founded sublattice
Let b denote the unboundedness number of ωω. That is, b is the smallest cardinality of a subset \(F \subseteq \omega ^\omega \) ...
-
Article
Martin's axiom and \(\Delta^2_1\) well-ordering of the reals
Assuming an inaccessible cardinal \(\kappa\) , there is a generic extension in which \(MA + 2^{\aleph_0} = \kappa\) holds and the reals have a
-
Article
A note on Dilworth's theorem in the infinite case
If ℘ is a poset and every antichain is finite, and if the length of the well-founded poset of antichains is less than ω2 1, then ℘ is the union of countably many chains. We also compute the length of the poset of...
-
Article
Initial segments of the degrees of size ℵ1
We settle a series of questions first raised by Yates at the Jerusalem (1968) Colloquium on Mathematical Logic by characterizing the initial segments of the degrees of unsolvability of size ℵ1: Every upper semi-l...