title: How to manipulate strings in prolog?
body: <p>I have this fact in my base
  fact("name","surname","123").
  if i simply write this question:
  fact(X,_,_). For X I get some unidentified output. 
  How can I retrieve any of this values, or how to get this output?
  ?-fact(X,_,_).
  output: name.</p>
  
  <p>Thanks ahead.</p>