1. NEED TO GO THROUGH A FILTER.
Company[
    Manages(@Manager=x1,@Depart=x2,@startDate=x3)]
:-
Employee(Y1),Manages(Y2),Department(Y3),
worksFor(Y1,Y3),manager(Y1,Y2),ssn(Y1,x1),
startDate(Y2,x3),dnumber(Y3,x2).

2. NEED TO GO THROUGH A FILTER.
Company[
    Manages(@Manager=x1,@Depart=x2,@startDate=x3)]
:-
Employee(Y1),Manages(Y2),Department(Y3),
manager(Y1,Y2),departmentManaged(Y2,Y3),ssn(Y1,x1),
startDate(Y2,x3),dnumber(Y3,x2).