ture. Even if the integral does not involve some of these, they must still be supplied some value. The most efficient will be a zero-length array or vector, which can be created with rep_array(0, 0) and rep_vector(0, 0), respectively. Other options include an uninitialized variable declared with size 0, which is equivalent to the above, or any easy value, such as size 1 array created with {0}.</p>
<section id="calling-the-integrator" class="level2">
<h2 class="anchored" data-anchor-id="calling-the-integrato