Fucking == in CLOS method combinations

combo==.lisp

(define-method-combination eql-combinator (&optional (order ':most-specific-last))
    ((around (:=) :order order)
     (primary (eql-combinator) :order order :required t))
  (if around
      `(and ,@(mapcar (lambda (method)
                        `(call-method ,method))
                      around))
      `(call-method ,(first primary))))


(defgeneric == (a b)
  (:method-combination eql-combinator))

(defmethod == eql-combinator (a b)
  (error "Equality undefined"))


(defclass a ()
  ((val :type integer
        :accessor val
        :initarg :val)))


(defclass b (a)
  ((name :type string
         :accessor name
         :initarg :name)))


(defclass c ()
  ((b :type b
      :accessor b
      :initarg :bl)))


(defclass d () ())

(defmethod == := ((x a) (y a))
  (print "Checking a")
  (= (val x) (val y)))

(defmethod == := ((x b) (y b))
  (print "Checking b")
  (string= (name x) (name y)))

(defmethod == := ((x c) (y c))
  (print "Checking c")
  (== (b x) (b y)))