v class="line"><a name="l00110"></a><span class="lineno">  110</span>&#160;    <span class="comment">! is free, and the last can only move within the xy-plane. This ensures the </span></div>
<div class="line"><a name="l00111"></a><span class="lineno">  111</span>&#160;    <span class="comment">! overall translation and rotational degrees of freedom are constrained</span></div>
<div class="line"><a name="l00112"></a><span class="lineno">  112</span>&#160;    <span class="comment">!</span></div>
<div class="l