metic operators are presented using C++ notation. For
instance <code>operator+(x,y)</code> refers to the binary addition operator and
<code>operator-(x)</code> to the unary negation operator. In Stan programs,
these are written using the usual infix and prefix notations as <code>x + y</code> and <code>-x</code>, respectively.</p>
<div id="binary-infix-operators-1" class="section level3">
<h3 number="3.6.1"><span class="header-section-number">3.6.1</span> Binary Infix Operators</h3>
<!-- real; operator+; (re