e>real</code> <strong><code>operator+</code></strong><code>(real x, real y)</code><br>Return the sum of x and y. <span class="math display">\[ (x + y) = \text{operator+}(x,y) = x+y \]</span></p>
<!-- real; operator-; (real x, real y); -->

<p><code>real</code> <strong><code>operator-</code></strong><code>(real x, real y)</code><br>Return the difference between x and y. <span class="math display">\[ (x - y) =
\text{operator-}(x,y) = x - y \]</span></p>
<!-- real; operator*; (real x, real y); -->

<p><code>re