definition missing complaint

core.clj

ns rt.core
  (:refer-clojure :exclude [+ - * /])
  (:require [clojure.core.typed :as typed
             :refer [ann ann-datatype ann-form ann-record check-ns tc-ignore]])
  (:require [clojure.algo.generic.arithmetic :as arith :refer [+ - * /]]))

(ann-record Vec3 [x :- Number y :- Number z :- Number])
(defrecord Vec3 [x y z])

(ann ^:no-check clojure.algo.generic.arithmetic/+ [Vec3 Vec3 -> Vec3])
(defmethod + [Vec3 Vec3]
  [{x :x y :y z :z} {a :x b :y c :z}]
  (Vec3. (+ x a) (+ y b) (+ z c)))

(+ (Vec3. 1 2 3) (Vec3. 3 4 5))

;; (check-ns) :ok
~