<a href="https://en.wikipedia.org/wiki/Gottfried_Wilhelm_Leibniz" id="mwSA" rel="mw:WikiLink" title="Gottfried Wilhelm Leibniz">Leibniz</a> makes the first use of the <a href="https://en.wikipedia.org/wiki/Long_s" id="mwSQ" rel="mw:WikiLink" title="Long s">long s</a> (∫) as a symbol of the <a href="https://en.wikipedia.org/wiki/Integral" id="mwSg" rel="mw:WikiLink" title="Integral">integral</a> in <a href="https://en.wikipedia.org/wiki/Calculus" id="mwSw" rel="mw:WikiLink" title="Calculus">calculus</a>.