title: How to verify if a rule exists in a prolog file clause database
body: <p>I'm working on a college assignment where I must verify if a certain clause (as a fact or as a rule) exists in the current clause database.</p>
  
  <p>The idea is to use a rule whose head  is verify(+name, +arguments). This rule should be true if in the database exists another rule whose head is name(arguments)</p>
  
  <p>Any help would be greatly appreciated...</p>