-----------------------------------------
Performing Query: Likes[p,ComputerScience]
  query_or(Likes[p,ComputerScience], {})
  -----------------------------
  Rule(premises=[Likes[x,Programming], Likes[x,Math]], conclusion=Likes[x,ComputerScience])
    query_and([Likes[x,Programming], Likes[x,Math]], {'x': 'p'})
      query_or(Likes[p,Programming], {'x': 'p'})
      Rule(premises=[], conclusion=Likes[Steve,Programming])
      query_or(Likes[p,Programming], {'x': 'p', 'p': 'Steve'}) return: [{'x': 'p', 'p': 'Steve'}]
    rest: [Likes[x,Math]]
      query_and([Likes[x,Math]], {'x': 'p', 'p': 'Steve'})
        query_or(Likes[p,Math], {'x': 'p', 'p': 'Steve'})
        Rule(premises=[], conclusion=Likes[Sally,Math])
        query_or(Likes[p,Math], {'x': 'p', 'p': 'Sally'}) return: [{'x': 'p', 'p': 'Sally'}]
      rest: []
        query_and([], {'x': 'p', 'p': 'Sally'})
        query_and([], {'x': 'p', 'p': 'Sally'}) return: [{'x': 'p', 'p': 'Sally'}]
      query_and([Likes[x,Math]], {'x': 'p', 'p': 'Sally'}) return: [{'x': 'p', 'p': 'Sally'}]
    query_and([Likes[x,Programming], Likes[x,Math]], {'x': 'p', 'p': 'Steve'}) return: [{'x': 'p', 'p': 'Sally'}]
    query_and([Likes[x,Programming], Likes[x,Math]], {'x': 'p', 'p': 'Steve'})
      query_or(Likes[p,Programming], {'x': 'p', 'p': 'Steve'})
      Rule(premises=[], conclusion=Likes[Steve,Programming])
      query_or(Likes[p,Programming], {'x': 'p', 'p': 'Steve'}) return: [{'x': 'p', 'p': 'Steve'}]
    rest: [Likes[x,Math]]
      query_and([Likes[x,Math]], {'x': 'p', 'p': 'Steve'})
        query_or(Likes[p,Math], {'x': 'p', 'p': 'Steve'})
        Rule(premises=[], conclusion=Likes[Sally,Math])
        query_or(Likes[p,Math], {'x': 'p', 'p': 'Sally'}) return: [{'x': 'p', 'p': 'Sally'}]
      rest: []
        query_and([], {'x': 'p', 'p': 'Sally'})
        query_and([], {'x': 'p', 'p': 'Sally'}) return: [{'x': 'p', 'p': 'Sally'}]
      query_and([Likes[x,Math]], {'x': 'p', 'p': 'Sally'}) return: [{'x': 'p', 'p': 'Sally'}]
    query_and([Likes[x,Programming], Likes[x,Math]], {'x': 'p', 'p': 'Steve'}) return: [{'x': 'p', 'p': 'Sally'}]
  -----------------------------
  Rule(premises=[Likes[x,Programming], Plays[x,ComputerGames]], conclusion=Likes[x,ComputerScience])
    query_and([Likes[x,Programming], Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'})
      query_or(Likes[p,Programming], {'x': 'p', 'p': 'Steve'})
      Rule(premises=[], conclusion=Likes[Steve,Programming])
      query_or(Likes[p,Programming], {'x': 'p', 'p': 'Steve'}) return: [{'x': 'p', 'p': 'Steve'}]
    rest: [Plays[x,ComputerGames]]
      query_and([Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'})
        query_or(Plays[p,ComputerGames], {'x': 'p', 'p': 'Steve'})
        query_or(Plays[p,ComputerGames], {'x': 'p', 'p': 'Steve'}) return: []
      query_and([Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'}) return: []
    query_and([Likes[x,Programming], Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'}) return: []
    query_and([Likes[x,Programming], Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'})
      query_or(Likes[p,Programming], {'x': 'p', 'p': 'Steve'})
      Rule(premises=[], conclusion=Likes[Steve,Programming])
      query_or(Likes[p,Programming], {'x': 'p', 'p': 'Steve'}) return: [{'x': 'p', 'p': 'Steve'}]
    rest: [Plays[x,ComputerGames]]
      query_and([Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'})
        query_or(Plays[p,ComputerGames], {'x': 'p', 'p': 'Steve'})
        query_or(Plays[p,ComputerGames], {'x': 'p', 'p': 'Steve'}) return: []
      query_and([Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'}) return: []
    query_and([Likes[x,Programming], Plays[x,ComputerGames]], {'x': 'p', 'p': 'Steve'}) return: []
  query_or(Likes[p,ComputerScience], {'x': 'p', 'p': 'Steve'}) return: [{'x': 'p', 'p': 'Sally'}, {'x': 'p', 'p': 'Sally'}]
Result: [{'p': 'Sally'}]