43 research outputs found

    Wider Thin-Very Tall Superatomic Boolean Algebras

    Full text link
    For each regular cardinal k > w we show the consistent existence of a thin very tall superatomic Boolean algebra of width k.Comment: There is a gap in claim 4.

    On constructions with 22-cardinals

    Full text link
    We propose developing the theory of consequences of morasses relevant in mathematical applications in the language alternative to the usual one, replacing commonly used structures by families of sets originating with Velleman's neat simplified morasses called 22-cardinals. The theory of related trees, gaps, colorings of pairs and forcing notions is reformulated and sketched from a unifying point of view with the focus on the applicability to constructions of mathematical structures like Boolean algebras, Banach spaces or compact spaces. A new result which we obtain as a side product is the consistency of the existence of a function f:[λ++]2→[λ++]≤λf:[\lambda^{++}]^2\rightarrow[\lambda^{++}]^{\leq\lambda} with the appropriate λ+\lambda^+-version of property Δ\Delta for regular λ≥ω\lambda\geq\omega satisfying λ<λ=λ\lambda^{<\lambda}=\lambda.Comment: Minor correction
    corecore