shell> curl -X DELETE --dump - http://localhost:8529/_api/aqlfunction/myfunction::x::y

HTTP/1.1 404 Not Found
content-type: application/json; charset=utf-8

{ 
  "error" : true, 
  "code" : 404, 
  "errorNum" : 1582, 
  "errorMessage" : "user function '%s()' not found" 
}