breakpoint when no debugger is present

Describe the possibility of abend.

Author: Hubert Tong

source/diagnostics.tex

@@ -2452,7 +2452,7 @@
 program is either terminated by the debugger or the debugger resumes execution
 of the program as if the function was not invoked. In particular, there is no
 intent for a call to this function to accomodate resumption of the program in a
-different manner.
+different manner. If there is no debugger present, the program can abend.
 \end{note}
 
 \end{itemdescr}