title: conditional component declaration and a following if equation
body: <p>I am trying to build a model that will have slightly different equations based on whether or not certain components exist (in my case, fluid ports).</p>
  
  <p>A code like the following will not work:</p>
  
  <pre><code>parameter Boolean use_component=false;
  Component component if use_component;
  equation
  if use_component then
    component.x = 0;
  end if;
  </code></pre>
  
  <p>How can I work around this?</p>