assoc
Name
assoc -- Returns the association of an object in an associative list
Synopsis
(assoc obj alist)
Description
Given an associative list, returns the pair that has obj as a car
or #f if no such pair exists.
- obj
- The associative key to locate. 
- alist
- The associative list. 
Example
(assoc "a" (("a" "b") ("c" "d"))) returns  ("a" "b")
Author
Norman Walsh, <ndw@nwalsh.com>
Source Code
(define (assoc obj alist)
  ;; Returns the association of an object in an associative list
  (let loop ((al alist))
    (if (null? al)
	#f
	(if (equal? obj (car (car al)))
	    (car al)
	    (loop (cdr al))))))