* (defgeneric a-fn (x))
#<STANDARD-GENERIC-FUNCTION A-FN (0) {5815ACB9}>

* (defmethod a-fn (x) :default-method)
#<STANDARD-METHOD A-FN (T) {581DB535}>

* (defmethod a-fn ((x number)) :a-number)
#<STANDARD-METHOD A-FN (NUMBER) {58241645}>

* (defmethod a-fn ((x (eql 1))) :number-1)
#<STANDARD-METHOD A-FN ((EQL 1)) {582A7D75}>

* (a-fn nil)
:DEFAULT-METHOD

* (a-fn "1")
:DEFAULT-METHOD

* (a-fn 0)
:A-NUMBER

* (a-fn 1)
:NUMBER-1