enqueued:	10	t : 1	[from bl:=1]
queue:	10	t : 1	[from bl:=1]
WARNING: unstable `t'+
rule: [after 10]	wl:1 & bl:0<0><0> -> t+:X
>> cause: `bl' (val: 0)
queue:	10	t : 0	[from bl:=1]	(weak)
	10	t : 0	[by bl:=0]
