RE: Difference between required topic and exclusive topic

Thanks.  This is great explanation.

Well, I have 2 queries.

Once exclusive topic is set (user said "Lets talk about sports"),  then how do I set it null? if someone ask What? and answer is "are we talking about sports", will it reset exclusiveness as this answer has just topic and not exclusive.

One more thing is, I don't want any answer without topic (due to conflicting answers for same question across topic). So I have set "required topic" for all responses and I ask user to select topic first. How do I set topic before user ask anything? As soon as chat starts, I want to set some default topic and then on User can change topic and all response from that topic will be answered. How do i achieve that?