Ulam matrix
In
weakly inaccessible.[1]
Definition
Suppose that κ and λ are cardinal numbers, and let be a -complete filter on . An Ulam matrix is a collection of subsets of indexed by such that
- If then and are disjoint.
- For each , the union over of the sets , is in the filter .
References
- Zbl 1007.03002
- Ulam, Stanisław (1930), "Zur Masstheorie in der allgemeinen Mengenlehre", Fundamenta Mathematicae, 16 (1): 140–150