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Xavier Labouze
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- TL;DR Summary
- Given A, a set (note P(A) its powerset) and A1, A2... Ak, k subsets of A. What is the cardinality of P(A1)∪P(A2)∪...∪P(Ak) ?
Mentor note: In this thread I (Mark44) have edited "cardinal" to "cardinality." In English, we talk about the "cardinality of a set," not the "cardinal of the set."
Given A a set of n elements - note |A| its cardinal and P(A) its powerset. Let A1, A2... Ak, be k subsets (not empty) of A.
What is the cardinality of P(A1)∪P(A2)∪...∪P(Ak) ? - Is there a formula or a rapid algorithm to compute it ? (I don't see how to compute it in polynomial time when the subsets are not pairwise disjoint...)
Thank you.
Given A a set of n elements - note |A| its cardinal and P(A) its powerset. Let A1, A2... Ak, be k subsets (not empty) of A.
What is the cardinality of P(A1)∪P(A2)∪...∪P(Ak) ? - Is there a formula or a rapid algorithm to compute it ? (I don't see how to compute it in polynomial time when the subsets are not pairwise disjoint...)
Thank you.
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