Miscellany

<Machine>
<define name="sphere"><Sphere args="0,0,0,1"/></define>
<define name="cylinder"><CylinderZ args="0,1,2,1"/></define>

<define name="inner">
    <HalTranslate var="y" x="0" y="1" z="0">
	<use name="sphere"/>
	<HalTranslate var="z" x="0" y="0" z="1">
	    <use name="cylinder"/>
	</HalTranslate>
    </HalTranslate>
</define>

<use name="sphere"/>
<HalTranslate var="x" x="1" y="0" z="0">
    <use name="sphere"/>
    <use name="inner"/>
</HalTranslate>
</Machine>