ectly,
     for i = 0, 1, for j = 1, 2, 3, 4, and for r, s, t
     in B, the following sort of schema:

     |   (L&lt;i&gt;-row L&lt;i&gt;-row&lt;j&gt;)
     |   (x L&lt;i&gt;-row&lt;j&gt; r)
     |   (y L&lt;i&gt;-row&lt;j&gt; s)
     |   (z L&lt;i&gt;-row&lt;j&gt; t)

     is intended to say that:

     |   L&lt;i&gt;-row&lt;j&gt; is a row in L&lt;i&gt;
     |   and the x position in L&lt;i&gt;-row&lt;j&gt; is r
     |   and the y position in L&lt;i&gt;-row&lt;j&gt; is s
     |   and the z position in L&