-style: italic;">x</span><sub>1</sub>&nbsp;&isin;&nbsp;<span style="font-style: italic;">X<sub>1</sub></span>)</span></sub>&nbsp;(&phi;)</td><td>&nbsp;&nbsp;&nbsp;</td><td><span style="font-family: courier new,courier,monospace;">(forall&nbsp;((X0&nbsp;x0)&nbsp;(X1&nbsp;x1))&nbsp;P)</span></td></tr>
<tr class="middle"><td align="right">existential</td><td>&nbsp;&nbsp;&nbsp;</td><td align="right">&exist;<sub><span style="font-size: x-small;"><span style="font-style: italic;">x</span><sub>0</sub>&nbsp;&isin;&