	0	_p : 0
	0	w : 0
	10	_bl : 1	[by w:=0]
	20	h.bl_stat : 0	[by _bl:=1]
	20	_p : 1
causing weak interference 
	20	w : X
WARNING: weak-interference `h.bl_stat'
>> cause: `_bl' (val: X)
	30	_bl : X	[by w:=X]
	40	h.bl_stat : X	[by _bl:=X]
restoring... 
	40	w : 1
	50	_bl : 0	[by w:=1]
	60	h.bl_stat : 1	[by _bl:=0]
pull-dn off 
	60	w : 0
unknown precharge 
	60	_p : X
WARNING: weak-interference `h.bl_stat'
>> cause: `_bl' (val: X)
	70	_bl : X	[by _p:=X]
	80	h.bl_stat : X	[by _bl:=X]
on precharge 
	80	_p : 0
	90	_bl : 1	[by _p:=0]
	100	h.bl_stat : 0	[by _bl:=1]
time: 100
