</span>,2)

<span class="keyword">switch</span> eT
    <span class="keyword">case</span> +1
        banb.addcoupling(<span class="string">'mat'</span>,<span class="string">'J3'</span>,<span class="string">'bond'</span>,4)
        banb.addcoupling(<span class="string">'mat'</span>,<span class="string">'J5'</span>,<span class="string">'bond'</span>,5)
    <span class="keyword">case</span> -1
        banb.addcoupling(<span class="string">'mat'</span>,<span class="string">'J3'</span>,<span class="string">'bond'