




A system is defined with a 
defsystem
 form in an ordinary Lisp source file. This form must be loaded into the Lisp image in order to define the system in the environment. Once loaded, operations can be carried out on the system by invoking Lisp functions, or, more conveniently, by using the system browser.
CL-USER 5 > (compile-system 'debug-app :force t)
would compile every file in a system called 
debug-app
. 
Note: When defining a hierarchy of systems, the leaf systems must be defined first -- that is, a system must be declared before any systems that include it.
By convention, system definitions are placed in a file called 
defsys.lisp
 which usually resides in the same directory as the members of the system.
The full syntax of 
defsystem
 is given in the 
LispWorks Reference Manual
. Below is a brief introduction.