ass="identifier">unit</span><span class="special">&lt;</span> <span class="identifier">Dim</span><span class="special">,</span> <span class="identifier">System</span> <span class="special">&gt;</span><span class="special">,</span> <span class="identifier">static_rational</span><span class="special">&lt;</span> <span class="identifier">N</span><span class="special">,</span> <span class="identifier">D</span> <span class="special">&gt;</span><span class="special">&gt;</span> <span class="special">{</span>
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