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