We have the following indirect implication of form equivalence classes:
| Implication | Reference |
|---|---|
| 303 \(\Rightarrow\) 50 |
Some propositions equivalent to the Sikorski extension theorem for Boolean algebras, Bell, J.L. 1988, Fund. Math. |
| 50 \(\Rightarrow\) 14 |
A survey of recent results in set theory, Mathias, A.R.D. 1979, Period. Math. Hungar. |
| 14 \(\Rightarrow\) 52 |
On the application of Tychonoff's theorem in mathematical proofs, L o's, J. 1951, Fund. Math. Two applications of the method of construction by ultrapowers to analysis, Luxemburg, W.A.J. 1970, Proc. Symp. Pure. Math. Applications of Model Theory to Algebra, Analysis and Probability, Luxemburg, 1969, 123-137 |
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement |
|---|---|
| 303: | If \(B\) is a Boolean algebra, \(S\subseteq B\) and \(S\) is closed under \(\land\), then there is a \(\subseteq\)-maximal proper ideal \(I\) of \(B\) such that \(I\cap S= \{0\}\). |
| 50: | Sikorski's Extension Theorem: Every homomorphism of a subalgebra \(B\) of a Boolean algebra \(A\) into a complete Boolean algebra \(B'\) can be extended to a homomorphism of \(A\) into \(B'\). Sikorski [1964], p. 141. |
| 14: | BPI: Every Boolean algebra has a prime ideal. |
| 52: | Hahn-Banach Theorem: If \(V\) is a real vector space and \(p: V \rightarrow {\Bbb R}\) satisfies \(p(x+y) \le p(x) + p(y)\) and \((\forall t > 0)( p(tx) = tp(x) )\) and \(S\) is a subspace of \(V\) and \(f:S \rightarrow {\Bbb R}\) is linear and satisfies \((\forall x \in S)( f(x) \le p(x) )\) then \(f\) can be extended to \(f^{*} : V \rightarrow {\Bbb R}\) such that \(f^{*}\) is linear and \((\forall x \in V)(f^{*}(x) \le p(x))\). |
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