1. NEED TO GO THROUGH A FILTER.
Company[
    WorksOn(@Project=x1,@Worker=x2,@hours=x3)]
:-
Project(Y1),Employee(Y2),WorksOn(Y3),
project(Y3,Y1),worker(Y3,Y2),pnumber(Y1,x1),
ssn(Y2,x2),hours(Y3,x3).