We have the following indirect implication of form equivalence classes:
Implication | Reference |
---|---|
407 \(\Rightarrow\) 14 |
Effective equivalents of the Rasiowa-Sikorski lemma, Bacsich, P. D. 1972b, J. London Math. Soc. Ser. 2. |
14 \(\Rightarrow\) 139 | |
139 \(\Rightarrow\) 137-k |
Cancellation laws for surjective cardinals, Truss, J. K. 1984, Ann. Pure Appl. Logic |
Here are the links and statements of the form equivalence classes referenced above:
Howard-Rubin Number | Statement |
---|---|
407: | Let \(B\) be a Boolean algebra, \(b\) a non-zero element of \(B\) and \(\{A_i: i\in\omega\}\) a sequence of subsets of \(B\) such that for each \(i\in\omega\), \(A_i\) has a supremum \(a_i\). Then there exists an ultrafilter \(D\) in \(B\) such that \(b\in D\) and, for each \(i\in\omega\), if \(a_i\in D\), then \(D\cap\ A_i\neq\emptyset\). |
14: | BPI: Every Boolean algebra has a prime ideal. |
139: | Using the discrete topology on 2, \(2^{\cal P(\omega)}\) is compact. |
137-k: | Suppose \(k\in\omega-\{0\}\). If \(f\) is a 1-1 map from \(k\times X\) into \(k\times Y\) then there are partitions \(X = \bigcup_{i \le k} X_{i} \) and \(Y = \bigcup_{i \le k} Y_{i} \) of \(X\) and \(Y\) such that \(f\) maps \(\bigcup_{i \le k} (\{i\} \times X_{i})\) onto \(\bigcup_{i \le k} (\{i\} \times Y_{i})\). |
Comment: