28.5 Invalidation Notices
The following annotations say that certain pieces of state may have
changed.
     
- ^Z^Zframes-invalid
- 
The frames (for example, output from the backtracecommand) may
have changed.
 
 
- ^Z^Zbreakpoints-invalid
- 
The breakpoints may have changed.  For example, the user just added or
deleted a breakpoint.