Definition talk:Set Union

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Perhaps you should extend the definition of the indexed union to generalize it so it's not just with Natural numbers (correct me if this has already been done). Andrew Salmon 21:56, 1 December 2011 (CST)

Last bit of generalised notation "if S is a set of sets" should cover it, unless my limitations are shwoing again.--prime mover 00:16, 2 December 2011 (CST)
Actually, there is a different union as such:
$\bigcup _{x \in A} B _{x} = \{ y : \exists x \in A: y \in B _{x} \}$. You might notice that this generalizes the $x \in \N$. This notation also allows $\bigcup A$ to be written $\bigcup _{x \in A} x$ Andrew Salmon 22:14, 2 December 2011 (CST)
Oh yeah the union on an indexing set. Feel free to amend it. --prime mover 00:20, 3 December 2011 (CST)