Presents recursion as a special case of the top-down approach to problem solving 
Explains recursive programs 
how to understand them 
how to simulate them 
how to write them 
Shows how recursive programs may be translated by a compiler or written in a non-recursive language 
Introduces two more data structures 
the stack 
the queue 
Illustrates the use of a stack with operations 
setstack 
empty 
push 
pop 
Case study梒hecking sequences for proper nesting 
uses the stack and treats it as a data abstraction 
4.3: A Close Look at the Execution of Recursive Programs 
4.4: Implementing Recursive Programs 
4.6: Evaluation and Translation of Expressions 
4.8: Case Study: Checking Sequences for Proper Nesting