source: CIVL/mods/dev.civl.com/examples/por/invisibility_c3.cvl@ cb4d4f4

/* This is an example to test the robustness of our POR algorithm.
 * Deadlock will not be detected if invisibility rule (C3) is not
 * conformed. */ 
$input double a;

void process(int pid) {
  if (!pid)
    $when(a == 0) return;
  else {
    $when(1) return;
  }
}

int main() {
  $parfor(int i : 0..1)
    process(i);
  return 0;
}