Is this the correct way to create SQL assertion?

Question

in order to make the following type of assertion

create assertion assert  
check "EMPTY SET" = (select User         
     from Video  
     where date=current_date()  
     group by user  
having count(*) >= 10

is this assertion right?

create assertion assert  
check  0 = (select count(*)  
     from Video  
     where date=current_date()  
     group by user  
having count(*) >= 10