title: Labeling with time_out difference between Sicstus 4.2.3 and 4.3.0
body: <p>In Sicstus 4.2.3 it is possible to do like this:</p>
  
  <pre><code>| ?- X in 0..2, labeling( [minimize(X), time_out(1000, Lr)],[X] ). 
  X = 0,
  Lr = success ? yes
  | ?- 
  </code></pre>
  
  <p>If you do the same in Sicstus 4.3.0 you get:</p>
  
  <pre><code>| ?- X in 0..2, labeling( [minimize(X), time_out(1000, Lr)],[X] ). 
  X = 0 ? yes
  | ?- 
  </code></pre>
  
  <p>What happened to <code>Lr</code>  in 4.3.0?</p>
  
  <p>And how do you know if the solution you get in 4.3.0 is the optimal solution or if the solution is a non-optimal solution?</p>