"><em>N</em></span>, key_type<span class="emphasis"><em>N</em></span>)] 5-tuples
        declares the types, const types, get-expressions, set-expressions and key
        types of the elements that are part of the adapted fusion sequence. <code class="literal">get_expr<span class="emphasis"><em>N</em></span></code>
        is the expression that is invoked to get the <span class="emphasis"><em>N</em></span>th element
        of an instance of <code class="computeroutput"><span class="identifier">type_name</