Formal Function Definition
Kenneth E. Iverson

10.1  Variables in a Function Definition
   Local variables
10.2Recursive definition
10.3Functions for Handling Polynomials
10.4The Function def
   The representation of numbers
   Representation of functions
   Name conflicts
   The xy form of function definition
   Recursive definitions
   All definitions
   The ⍺⍵ form
   Argument conflicts and spaces
   Character input
   Summary
Exercises