Thread: Given this definition, is there one or two Rs?

The definition uses R for relation but I am wondering if the R near the "element of" symbol is also the "relation" notation or if it is used for "reals".

Sorry if this is a dumb question but any input would be greatly appreciated!
Thanks in advance!

It's all the same . Remember a relation can be written as ordered pairs:

.

So, the right hand side means "Point (a,b) is part of the relation R"?