for element types).
</li>
</ul>

<p>
If both types are bound type parameters, they unify per the given
matching modes if:
</p>

<ul>
<li>
	Both type parameters are identical.
</li>
<li>
	At most one of the type parameters has a known type argument.
	In this case, the type parameters are <i>joined</i>:
	they both stand for the same type argument.