mc-stan.org/docs/functions-reference/higher-order_functions.html#functions-ode-solver">view current version</a>.
</div>
<div id="functions-ode-solver" class="section level2">
<h2 number="9.2"><span class="header-section-number">9.2</span> Ordinary Differential Equation (ODE) Solvers</h2>
<p>Stan provides built-in ordinary differential equation (ODE) solvers.
Although they look like function applications, the ODE solvers are
special in two ways.</p>
<p>First, the first argument to each of the solvers is a fu