Consistency of the Boolean-algebra splitting property

Let Dω2D_{\omega_2} be the club filter on ω2\omega_2, and let FF be the function used in the source to associate to a subset of ω2\omega_2 the relevant set of ordinals. The property ()(*) asserts that for every stationary

A{α<ω2:cf(α)=ω}A\subseteq\{\alpha<\omega_2:{\rm cf}(\alpha)=\omega\}

and suitable B,CB,C with F(A)=BCF(A)=B\cup C, there are stationary disjoint A,BA',B' such that

A=AB,A=A'\cup B',

and

F(A)=B(modDω2),F(B)=C(modDω2).F(A')=B\pmod {D_{\omega_2}},\qquad F(B')=C\pmod {D_{\omega_2}}.

Consistency conjecture. The property ()(*) is consistent with ZFC.

The source presents this as a consistency assertion connected with quantifier elimination for the Boolean-algebraic structure coding the monadic theory of ω2\omega_2. The parser gives no resolution.

Sources & referencesView supporting material

Primary source

Saharon Shelah, “The monadic theory of order”, arXiv:2305.00968 (2023).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.