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]

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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

**Physics Forums | Science Articles, Homework Help, Discussion**