Exibir código-fonte para Chapter 02

* Chapter 2 Lexical Elements, Operators, and the C System 
** 2.1 Characters and Lexical Elements
** 2.2 Syntax Rules
** 2.3 Comments
** 2.4 Keywords
** 2.5 Identifiers
** 2.6 Constants
** 2.7 String Constants
** 2.8 Operators and Punctuators
** 2.9 Precedence and Associativity of Operators
** 2.10 Increment and Decrement Operators
** 2.11 Assignment Operators
** 2.12 An Example: Computing Powers of 2
** 2.13 The C System
*** The Preprocessor
*** The Standard Library