Computational Logic  

(Note that forms a complete lattice under  important for fixpoint operations to be introduced later).
We now turn to the operational semantics of logic programs,
given by a concrete operational procedure: Linear (Input)
Resolution.
father(john,mary)
grandfather(X,Y) father(X,Z), mother(Z,Y)
We abbreviate as
(in particular, if , then every element of is in , ).
}