(defun findmissing (fh)
  (maphash #'(lambda (askbid h)
               (format t askbid)
               (maphash #'(lambda (symbol h)
                            (format t symbol)
                            (let* ((years (hash-table-keys h))
                                   (minyear (apply #'min years))
                                   (maxyear (apply #'max years))
                                   (maphash #'(lambda (year h)
                                                (let* ((months (hash-table-keys h))
                                                       (startmonth (if (equal year minyear)
                                                                       (apply #'min months)
                                                                       1))
                                                       (endmonth (if (equal year maxyear)
                                                                     (apply #'max months)
                                                                     12)))
                                                  (format t "missing ~a"
                                                          (set-difference (iota
                                                                           (+ endmonth 1)
                                                                           :start startmonth)
                                                                          months))))
                                            h))))
                        h))
           fh))



1 compiler notes:

fx.lisp:56:25:
  style-warning: The variable H is defined but never used.

fx.lisp:61:36:
  error:
    The LET* binding spec (MAPHASH
                           #'(LAMBDA (YEAR H)
                               (LET* ((MONTHS (HASH-TABLE-KEYS H))
                                      (STARTMONTH
                                       (IF (EQUAL YEAR MINYEAR)
                                           (APPLY #'MIN MONTHS)
                                           1))
                                      (ENDMONTH
                                       (IF (EQUAL YEAR MAXYEAR)
                                           (APPLY #'MAX MONTHS)
                                           12)))
                                 (FORMAT T "missing ~a"
                                         (SET-DIFFERENCE
                                          (IOTA (+ ENDMONTH 1) :START STARTMONTH)
                                          MONTHS))))
                           H) is malformed.

Compilation failed.