breakRecursively start a new Prolog top level. This Prolog top level shares
everything from the environment it was started in. Debugging is switched
off on entering a break and restored on leaving one. The break
environment is terminated by typing the system's end-of-file character
(control-D). If that is somehow not functional, the term
end_of_file. can be entered to return from the break
environment. If the -t toplevel command line
option is given, this goal is started instead of entering the default
interactive top level (prolog/0).
Notably the gui based versions (swipl-win on Windows and
MacOS) provide the menu Run/New thread that opens a new toplevel
that runs concurrently with the initial toplevel. The concurrent
toplevel can be used to examine the program, in particular global
dynamic predicates. It can not access global variables or
thread-local dynamic predicates (see thread_local/1)
of the main thread.