title: Use of NOT where also using OR
body: <p>If used in a complex set of arguments, does the NOT condition apply only to the first argument or to all subsequent arguments?</p>
  
  <p>e.g. In the following fragment of a merge statement does the NOT operator only apply to the </p>
  
  <p><code>TGT.OrderID = SRC.OrderID</code> argument? </p>
  
  <p><a href="https://msdn.microsoft.com/en-us/library/ms190276.aspx" rel="nofollow">https://msdn.microsoft.com/en-us/library/ms190276.aspx</a> advises that NOT is evaluated before OR. 
  Does that mean that it is applied to all arguments or that I need a new one for every argument being negated - in which case I would need to add one to the fourth and seventh arguments.</p>
  
  <pre><code>WHEN MATCHED AND NOT TGT.OrderID = SRC.OrderID 
                OR(TGT.OrderID IS NULL AND SRC.OrderID IS NOT NULL)
                OR(TGT.OrderID IS NOT NULL AND SRC.OrderID IS NULL)
                OR TGT.EmpID = SRC.EmpID
                OR(TGT.EmpID IS NULL AND SRC.EmpID IS NOT NULL) 
                OR(TGT.EmpID IS NOT NULL AND SRC.EmpID IS NULL) 
                OR TGT.orderdate = SRC.OrderDate
                OR(TGT.Orderdate IS NULL AND SRC.Orderdate IS NOT NULL)
                OR(TGT.Orderdate IS NOT NULL AND SRC.Orderdate IS NULL)
  </code></pre>