equation (16) has a unique solution 
lying in a narrowing
backwards antifunnel between the lower fence 
and
the upper fence
.
Since all the functions are positive for negative t, the inequality
(17) can be integrated from t to 0.
Setting 
, we find
which gives
Exponentiating now gives
Therefore 
not only remains bounded, it tends to 0 exponentially
as 
:
![[Annotate]](/organics/icons/sannotate.gif){kind=icon}
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