The loop proper in this code is the foreach statement. But the foreach loop doesn’t stand on its own: the code in the loop body refers to variables declared in the two lines before the loop.9 And the work the loop does is all for naught without the if statement after the loop that actually reports the results. In Common Lisp, of course, the **LOOP** construct is an expression that returns a value, so there’s even more often a need to do something after the loop proper, namely, generate the return value.

After the initially or , these clauses consist of all the Lisp forms up to the start of the next loop clause or the end of the loop. All the initially forms are combined into a single prologue, which runs once, immediately after all the local loop variables are initialized and before the body of the loop. The finally forms are similarly combined into a epilogue to be run after the last iteration of the loop body. Both the prologue and epilogue code can refer to local loop variables.

• A return clause executes.
• The loop is terminated by an always, never, or thereis clause, as I’ll discuss in the next section.

Within the epilogue code, **RETURN** or can be used to explicitly provide a return value for the loop. Such an explicit return value will take precedence over any value that might otherwise be provided by an accumulation or termination test clause.

     (loop for item in list do