[top-level]
rules:
[after 10, unstable]	~a -> c+
[after 10, unstable]	a -> c-
	0	a : 1
	10	c : 0	[by a:=1]
	10	a : 0
queue:	20	c : 1	[from a:=0]
	10	a : 1
event c+ was silently overturned to c- 
WARNING: weak-interference `c'
>> cause: `a' (val: X)
	10	a : X
	20	c : X	[by a:=X]
initialize to X 
	20	a : 1
queue:	30	c : 0	[from a:=1]
	20	a : 0
	30	c : 1	[by a:=0]
event c- was silently overturned to c+ 
testing weak instability... 
No event pending on `c'.
WARNING: weak-interference `c'
>> cause: `a' (val: X)
	30	a : X
	40	c : X	[by a:=X]
should suppress c+ weak unstable 
c should still become X 
	40	a : 0
	50	c : 1	[by a:=0]
	50	a : 1
queue:	60	c : 0	[from a:=1]
WARNING: weak-interference `c'
>> cause: `a' (val: X)
	50	a : X
	60	c : X	[by a:=X]
should suppress c- weak unstable 
c should still become X 
