and <code>[]int</code> must match <code>[]E</code> of the constraint,
a compiler can infer that <code>E</code> must be <code>int</code>.
Thus, for these two equations, type inference infers
</p>

<pre>
	S ➞ Slice
	E ➞ int
</pre>

<p>
Given a set of type equations, the type parameters to solve for are
the type parameters of the functions that need to be instantiated