Solution SG 12

What is the voltage output from this circuit? You can assume that the gain element is powered from a sufficiently large (voltage) power supply. (Ref: A problem from Maxim-IC).
In[]:=
Limit[vo/.Solve[(​​(*inputto+*)(vo/3)-​​(*inputto-*)((2/3)vo-1)​​(*thedifferencetimes*))A==vo,vo],AInfinity]
Out[]=
{3}