**READING: I §3 2**
Back to reading**:**
I §3 1

*begin quote ita***"**

*CHAPTER I* [:]
**
Notions from Set Theory
**

These pages assume that the reader has the book and is reading along. topic index contents

Please read these notes from the beginning to here, and then paragraph 2 of §3.

The notation that is presented in paragraph 2 seems self explanatory, but is heavily dependent on being written on paper.

One fact which escapes mention is that *f*(*x*) is read '*f* of *x*'. Also: *x* is called the *argument* of the function.

Now please, in place of the next paragraph, recall the example from §1 that was postponed until after chapter two on the real number system. Essentially, paragraph 3 says that the rule which determines a function's values can be given, for example, by a list, by a mathematical equation, or by a not necessarily computable description. The specific facts used in the examples follow from chapter two, and are included in chapter one because of Rosenlicht's stated prerequisites. We can postpone this material.