Form equivalence class Howard-Rubin Number: 1
Statement:
For every family \(\{(X_i,T_i): i\in k\}\) of disjoint \(T_1\) topological spaces, the free union contains an open set \(O\) such that \(\emptyset\ne O\cap X_i\) and \( O\cap X_i\ne X_i\) for all\(i\in k\).
Howard-Rubin number: 1 BN
Citations (articles):
Keremedis [1998a]
Filters, antichains and towers in topological spaces and the axiom of choice
Connections (notes):
Note [77]
In this note we include definitions from
Keremedis [1998a] for forms [1 BL]
through [1 BR], [1CB],
and [67 G].
References (books):
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