SYNOPSIS
	void add_xverb(string str)

DESCRIPTION
	This function is connected to the add_action() function. It
	will set up the command str to trigger a call to the function
	set up by the previous call to add_action().
	
	add_xverb() differs from add_verb() in that only leading
	characters of the input line must match with str. It basically
	is the same as setting flag in add_action().

SEE ALSO
	add_action(E), query_verb(E), add_verb(E)