they must be <a href="#Type_identity">identical</a>.
		Otherwise, if neither of them is a defined type, they must
		have the same number of methods
		(unification of <code>A</code> and <code>T</code> already
		established that the methods match).
	</li>
	<li>
		Neither <code>A</code> nor <code>T</code> are interface types:
		In this case, if <code>T</code> is a defined type, <code>T</code>

</p>

<p>
If the effects of a goroutine must be observed by another goroutine,
use a synchronization mechanism such as a lock or channel
communication to establish a relative ordering.
</p>

<h3 id="chan">Channel communication</h3>

<p>
Channel communication is the main method of synchronization
between goroutines.  Each send on a particular channel