anchor.diff:  (define (lint:analyze-for-bugged-do expressions)
   
     (define (back-reference-found? expr previous-bindings)
  -    (format #t "e: ~A b: ~A~%" expr previous-bindings)
       (cond ((nil? expr)
              #f)
             ((atom? expr)
  
positive.code: (define (lint:analyze-for-bugged-let expressions)
  
    (define (back-reference-found? expr previous-bindings)
      (format #t "e: ~A b: ~A~%" expr previous-bindings)
      (cond ((nil? expr)
             #f)
            ((atom? expr)
  
negative.code: 
  ;;; Linter
  
  (define (expression-crawler expression car-test analyzer extract-for-recursion extract-for-analysis report)
    (cond ((nil? expression) report)
          ((atom? expression) report)
          ((list? expression)
           (if (car-test expression)
               (expression-crawler (extract-for-recursion expression)
                                   car-test
                                   analyzer
                                   extract-for-recursion
                                   extract-for-analysis
                                   (analyzer (extract-for-analysis expression) report))
               (list report
                     (expression-crawler (car expression) car-test analyzer extract-for-recursion extract-for-analysis '())
                     (expression-crawler (cdr expression) car-test analyzer extract-for-recursion extract-for-analysis '()))))
          (else report)))
  
  ;;; Analysis functions
  