title: Why does SWI-Prolog only give me the first answer?
body: <p>I'm new to Prolog. I'm just trying simple examples to learn. I have this <code>.pl</code> file with these lines:</p>
  
  <pre><code>parent(pam,bob).
  parent(tom,bob).
  parent(tom,lio).
  parent(bob,ann).
  parent(bob,pat).
  parent(pat,jim).
  </code></pre>
  
  <p>After consulting and testing, it only shows the first answer. For example:</p>
  
  <pre><code>5 ?- parent(X,Y).
  X = pam,
  Y = bob .
  </code></pre>
  
  <p>Isn't it supposed to give all the combinations that satisfy the relation <code>parent</code>? </p>
  
  <p>Do anyone have idea what the problem is?</p>