$Inspector

$Inspector
is a global variable which gives a function to apply when the inspector is invoked from an interrupt menu.

The argument supplied is the number of nested invocations of the inspector that are in use.

The default value:

Print a message before starting or exiting a subsession:

Invoke an interrupt menu:

In subsession:

Restore to the default value:

The default value:

Out[1]=

Print a message before starting or exiting a subsession:

Invoke an interrupt menu:

In subsession:

(Dialog) Out[3]=

Restore to the default value: