bound type parameter:
</p>

<pre>
	P<sub>k</sub> ➞ A<sub>k</sub>
</pre>

<p>
A type argument <code>A<sub>k</sub></code> may be a composite type,
containing other bound type parameters <code>P<sub>k</sub></code> as element types
(or even be just another bound type parameter).
In a process of repeated simplification, the bound type parameters in each type