{\displaystyle \int _{a}^{b}\!f(x)\,dx=F(b)-F(a).} The principles of integration were formulated independently by Isaac Newton and Gottfried Leibniz in the late 17th century, who thought of the integral as an infinite sum of rectangles of infinitesimal width.
amendment - a statement that is added to or revises or improves a proposal or document (a bill or constitution etc.) statement - a message that is stated or declared; a communication (oral or written) setting forth particulars or facts etc; according to his statement he was in London on that day.
An article is something that was part of the constitution as originally written. An amendment is something added to the constitution latter on to correct some perceived flaw. What are referred to as the Bill of Rights are amendments added to the constitution to get the states to ratify it in the first place.