the partial sum (inclusive), type <code>int</code></p></li>
<li><p><em><code>s1</code></em>, first shared argument, type <code>T1</code>, matching type of <code>s1</code> in <code>reduce_sum</code> (<code>reduce_sum_static</code>)</p></li>
<li><p><em><code>s2</code></em>, second shared argument, type <code>T2</code>, matching type of <code>s2</code> in <code>reduce_sum</code> (<code>reduce_sum_static</code>)</p></li>
<li><p><em><code>...</code></em>, remainder of shared arguments, with types matching those 