Chatbot in Prolog
===

I've been trying to create a chatbot (as an assignment) in prolog, so far I have made a database in a .pl file and I have listed a lot of possible conversations. 
I know that prolog works like this for example if we have 

    Chatbot(good) 

and we type 

    ?-Chatbot(good). 
it will respond 

    yes or ture.

Now I don't know how to use my database so that the program can work exactly as a chatbot for example without the need to write in appropriate syntax:

    Hello (typed by the user)

    Hi there, (typed by the program automatically)


My database is like this:

    answer( question, [
    [Yes, I am here]]).

    question ([are you there?]) 
