1. ## Lightening Bolt

What does that symbol mean guys?

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The circled symbol in the picture.

2. Originally Posted by JesseElFantasma
What does that symbol mean guys?

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The circled symbol in the picture.

There are gaps in the lines above and below, just to the left of the "symbol", that make me think something was left out in the picture. That is, that only part is shown. That, together with the captions, make me think it is simply an "R" with the vertical line missing. And that, of course, means the set of real numbers.

3. Thank you HallsofIvy!
I didn't notice that at all!