From the NannyMUD documentation

LAST CHANGE

2003-03-28

FUNCTION

NAME
        query_light - Query the total light level of an object.


LOCATION
        /obj/light (Inherited by most lib objects)

SYNTAX
	int query_light()

DESCRIPTION
	Returns the total light level of an object, including light levels
        contributed by everything contained within it.


EXAMPLE
	query_light() 
	  Return the light level of the current object plus everything
          contained within it.

	ob -> query_light()
	  Return the light level of ob plus everything contained within ob.


SEE ALSO
        add_light in sfun/add_light


SEE ALSO
        query_object_light in sfun/query_object_light