Prolog: declarative semantics. Let the following program be given: p(a). p(b). q(a,b). q(a,c). q(b,d). q(d,e). q(e,f). r(x,y):- p(x),q(z,x),q(z,y). s(x,y):- r(x,z),q(z,y). t(x,y):- p(x),q(x,z),q(z,y). u(x,y):- t(x,y). u(x,y):- u(x,z),q(z,y). a) Give the Herbrand universe HU and Herbrand base HB and then compute the first three iterations of the Intenliste Consequence Operntor: Tp(fai)= Tp(Tp(fai))= T^3p(fai)=Tp(Tp(fai))...