```common lisp
(cl:in-package #:asdf-user)

;;;; A CONCRETE SYNTAX TREE (or CST for short) is a representation of
;;;; a Common Lisp expression such that the source location of each
;;;; object in the expression can be associated with that object.
;;;;
;;;; This system contains functions for manipulating such
;;;; representations in various ways.
;;;;
;;;; Notice that there is obviously no way to distinguish between a
;;;; CST and a Common Lisp expression that happens to be an atom in
;;;; the form of a CST.  Client code that uses functions of this
;;;; system must therefore be sure that CSTs are being used.

(defsystem :cleavir-cst
  :depends-on (:cleavir-code-utilities
	       :alexandria
	       :smug)
  :serial t
  :components
  ((:file "packages")
   (:file "concrete-syntax-tree")
   (:file "complete")
   (:file "rebuild")
   (:file "declarations")
   (:file "body")
   (:file "lambda-list")))
```

Add new component to system definition.
user
```common lisp
(cl:in-package #:asdf-user)

;;;; A CONCRETE SYNTAX TREE (or CST for short) is a representation of
;;;; a Common Lisp expression such that the source location of each
;;;; object in the expression can be associated with that object.
;;;;
;;;; This system contains functions for manipulating such
;;;; representations in various ways.
;;;;
;;;; Notice that there is obviously no way to distinguish between a
;;;; CST and a Common Lisp expression that happens to be an atom in
;;;; the form of a CST.  Client code that uses functions of this
;;;; system must therefore be sure that CSTs are being used.

(defsystem :cleavir-cst
  :depends-on (:cleavir-code-utilities
	       :alexandria
	       :smug)
  :serial t
  :components
  ((:file "packages")
   (:file "concrete-syntax-tree")
   (:file "complete")
   (:file "rebuild")
   (:file "declarations")
   (:file "body")
   (:file "lambda-list")
   (:file "lambda-list-parsing")))
```
assistant