English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Using Ot, we construct a Boolean algebra B of power 81, with the following properties: (a) B has just Et1 subalgebras. (b) Every uncountable subset of B contains a countable independent set, a chain of order type q, and three distinct elements a, b and c, such that a n b = c. (a) refutes a conjecture of J. D. Monk, (b) answers a question of R. McKenzie. B is embeddable in P( w). A variant of the construction yields an almost J6nson Boolean algebra. We prove that every subalge- bra of an interval algebra is retractive. This answers affirmatively a conjecture of B. Rotman. Assuming MA or the existence of a Suslin tree we find a retractive BA not embeddable in an interval algebra. This refutes a conjecture of B. Rotman. We prove that an uncountable subalgebra of an interval algebra contains an uncountable chain or an uncountable antichain. Assuming CH we prove that the theory of Boolean algebras in Magidor's and Malitz's language is undecidable. This answers a question of M. Weese.

A Boolean algebra with few subalgebras, interval Boolean algebras and retractiveness