style="font-style: italic;">x</span>,&nbsp;<span style="font-style: italic;">y</span>)&nbsp;&isin;&nbsp;<span style="font-style: italic;">r</span> or <span style="font-style: italic;">r</span>(<span style="font-style: italic;">x</span>,&nbsp;<span style="font-style: italic;">y</span>)</td><td>&nbsp;&nbsp;&nbsp;</td><td><span style="font-family: courier new,courier,monospace;">(r&nbsp;x&nbsp;y)</span></td></tr>
<tr class="middle"><td align="right">&nbsp;function&nbsp;application</td><td>&nbsp;&nbsp;&nbsp;</t