title: Findall with multiple variables in Prolog
body: <p>I would like to get a list of solutions from a rule I made in Prolog.</p>
  
  <p>However the findall predicate appears to only work with one variable.</p>
  
  <p>Can anyone suggest how to get around this apparent limitation?</p>
  
  <p>My rule</p>
  
  <pre><code>beat(P,M,E)
  </code></pre>
  
  <p>What I want </p>
  
  <pre><code>L = [[P,M],[P,M],................]
  </code></pre>
  
  <p>What I get now </p>
  
  <pre><code>L = [P,P,P,P,.........]
  </code></pre>
  
  <p>or</p>
  
  <pre><code>L = [M,M,M,M,M.............]
  </code></pre>