(let ((mom-path
        (let ((mom-path
                (if (eq?
                     (ft-eye-color (make-ft 'emily 'brown 'unknown 'unknown))
                     'blue)
                  '()
                  (let ((mom-path
                          (path-to-blue-eyes
                            (ft-mom
                              (make-ft 'emily 'brown 'unknown 'unknown))))
                        (dad-path
                          (path-to-blue-eyes
                            (ft-dad
                              (make-ft 'emily 'brown 'unknown 'unknown)))))
                    (cond
                     ((and mom-path dad-path) (cons 'mom mom-path))
                     ((and mom-path (not dad-path)) (cons 'mom mom-path))
                     ((and dad-path (not mom-path)) (cons 'dad dad-path))
                     (else #f)))))
              (dad-path
                (path-to-blue-eyes
                  (ft-dad
                    (make-ft
                      'alice
                      'green
                      (make-ft 'emily 'brown 'unknown 'unknown)
                      (make-ft 'bruce 'blue 'unknown 'unknown))))))
          (cond
           ((and mom-path dad-path) (cons 'mom mom-path))
           ((and mom-path (not dad-path)) (cons 'mom mom-path))
           ((and dad-path (not mom-path)) (cons 'dad dad-path))
           (else #f))))
      (dad-path
        (path-to-blue-eyes
          (ft-dad
            (make-ft
              'robby
              'hazel
              (make-ft
                'alice
                'green
                (make-ft 'emily 'brown 'unknown 'unknown)
                (make-ft 'bruce 'blue 'unknown 'unknown))
              (make-ft 'bill 'brown 'unknown 'unknown))))))
  (cond
   ((and mom-path dad-path) (cons 'mom mom-path))
   ((and mom-path (not dad-path)) (cons 'mom mom-path))
   ((and dad-path (not mom-path)) (cons 'dad dad-path))
   (else #f)))