If you have followed this example from the beginning, the interface and its callbacks are now completely specified. Next, you can create a Common Lisp system which integrates the interface definition with the callback code.
:members ("ib-callbacks" "ib-example"))
This form creates a system called
ib-test that contains two members;
ib-example.lisp (the file containing the interface definition) and
ib-callbacks.lisp (the file containing the callback code).
ib-callbacks.lispfiles, and call this file
LispWorks IDE User Guide (Windows version) - 13 Sep 2017