spy_message( needed, Store ) :-
	single_enquiry_for_store( act(Active), Store ),
	member( Var-Data, Active ),
	data_choose( nds(VarNds), Data ),
	write( Var ), write( ', needs : ' ), write( VarNds ), nl, fail.

spy_message( active, Store ) :-
	single_enquiry_for_store( act(Active), Store ),
	member( Var-Data, Active ),
	write( Var ), write( ', has data : ' ), write( Data ), nl, fail.

spy_message( _A, _B ) :- !.