```common lisp
(defsystem #:lindsey
  ;;:depends-on ()
  :serial t
  :components ((:file "package")
	       (:file "Point2D")
	       ;(:file "Vector2D")
	       ;(:file "Polynomial")
	       ;(:file "Intersections")
	       ))
```

Rename files to lower case and add vector2d file
user
```common lisp
(defsystem #:lindsey
  ;;:depends-on ()
  :serial t
  :components ((:file "package")
	       (:file "point2d")
	       (:file "vector2d")
	       ;;(:file "Polynomial")
	       ;;(:file "Intersections")
	       ))
```
assistant