Unfamiliar Notation: \bigcup & \bigcap Explained

[Lank]

Homework Statement

Having trouble recognizing this notation.
Let Ai = {i, i + 1, i + 2, . . . } for i = 1, 2, . . . . What
are:

∞
$$\bigcup$$ A (subscript i)
i=1

and

∞
$$\bigcap$$ A (subscript i)
i=1

Homework Equations

I know what the $$\bigcup$$ or $$\bigcap$$ notation means in sets and subsets, but not in sequences and summations.

The Attempt at a Solution

I don't need it explained, I simply need to know what the $$\bigcup$$ and $$\bigcap$$ stands for so I can read up on them. Thanks guys. I can also upload the pdf attachment if needed.

 

[Mark44]

$$\bigcup$$ - union - A₁ U A₂ U ... U A_n
$$\bigcap$$ - intersection - same as above but with the intersection symbol

 

[Lank]

Thanks.