Horn Clauses
From Wikipeida
Horn clauses are also the basis of logic programming, where it is
common to write definite clauses in the form of an implication:
In fact, the resolution of a goal clause with a definite clause to
produce a new goal clause is the basis of the SLD resolution inference
rule, used to implement logic programming and the programming language
Prolog.
EDIT
Since OP is trying to relate predicates (first-order predicate logic) to horn clauses
See: Translation of first-order predicate logic to horn clause logic: in Logic Programming by Anthony A. Aaby
I tried to reproduce the instructions here to avoid link rot, but I could not figure out how to put a list in a quoted section.