tifier">X</span><span class="special">&gt;</span></code> is interoperable with <code class="computeroutput"><span class="identifier">filter_iterator</span><span class="special">&lt;</span><span class="identifier">P2</span><span class="special">,</span> <span class="identifier">Y</span><span class="special">&gt;</span></code>
        if and only if <code class="computeroutput"><span class="identifier">X</span></code> is interoperable
        with <code class="computeroutput"><span class="identifier">Y</span>