Was lucky enough to take Serge's class when he was visiting UC Berkeley back in the 90's. And yet I'm still writing SQL :( Curious to know what the state in the

Was lucky enough to take Serge's class when he was visiting UC Berkeley back in the 90's. And yet I'm still writing SQL :( Curious to know what the state in the art in solving the then-thornier theoretical problems (negation mostly) is.