Abstract
Let B be a superatomic Boolean algebra. B is well generated, if it has a well founded sublattice L such that L generates B. The free product of Boolean algebras B and C is denoted by B * C. If C is a chain then B(C) denotes the interval algebra over C. THEOREM 1: (a) Every Boolean subaJgebra of B(א1) * B(א0) is wellgenerated. (b) B(א1) * B(א1) contains a non well-generated Boolean subalgebra. Canonical well-generatedness is defined in the introduction. Recall that B(א1) * B(א0) is canonically well-generated, and thus well-generated. We prove the following result. THEOREM 2: B(א1) * B(א0) contains a non canonically well generated Boolean subalgebra. In contrast with Theorem 1(b), we have the following result. THEOREM 3: Let A = {aα: α < א1} ⊆ ℘(ω) be a strictly increasing sequence in the relation of almost containment. Let B be the subalgebra of ℘(ω) generated by {{n}: n ∈ א0} ∪ A. Then B is superatomic, and B is not embeddable in a well-generated algebra.
Original language | English |
---|---|
Pages (from-to) | 299-326 |
Number of pages | 28 |
Journal | Israel Journal of Mathematics |
Volume | 135 |
DOIs | |
State | Published - 1 Jan 2003 |
ASJC Scopus subject areas
- General Mathematics