I'm trying to read this book "Automata, Computability, and Complexity" by Elaine Rich and on page 75 it defines this function: [itex]\delta'(Q,c) = \cup\{eps(p):\exists q\in Q((q,c,p)\in\Delta)\}[/itex](adsbygoogle = window.adsbygoogle || []).push({});

I've never seen the union operator used in this way. What does it mean?

Apologies if this is in the wrong section.

Edit: I don't care what the stuff inside the brackets means. I understand that part. I'm asking, what does [itex]\cup[/itex] mean when it's front of any set? It could be something like [itex]\cup\{x:x\in\mathbb{R}\}[/itex]

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# Meaning of a union symbol in front of a set?

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