Qué (quién) es definite clause - definición
CLAUSE (A DISJUNCTION OF LITERALS) WITH AT MOST ONE POSITIVE, I.E. UNNEGATED, LITERAL
Horn logic; Definite clause; Horn sentence; Horn clauses; Dual-Horn clause; Horn formula; Universal Horn theory; Horn Logic
definite clause
<logic> A Horn clause that has exactly one {positive
literal}.
(2000-01-24)
Definite clause grammar
MEANS OF EXPRESSING GRAMMATICAL RELATIONSHIPS
Definite clause grammars; Context-sensitive definite clause grammars
A definite clause grammar (DCG) is a way of expressing grammar, either for natural or formal languages, in a logic programming language such as Prolog. It is closely related to the concept of attribute grammars / affix grammars from which Prolog was originally developed.
Horn clause
<logic> A set of atomic literals with at most one {positive
literal}. Usually written
L < - L1, ..., Ln
or
< - L1, ..., Ln
where n >= 0, " < - " means "is implied by" and comma stands for
conjuction ("AND"). If L is false the clause is regarded as
a goal. Horn clauses can express a subset of statements of
first order logic.
The name "Horn Clause" comes from the logician Alfred Horn,
who first pointed out the significance of such clauses in
1951, in the article "On sentences which are true of direct
unions of algebras", Journal of Symbolic Logic, 16, 14-21.
A definite clause is a Horn clause that has exactly one
positive literal.
(2000-01-24)
Wikipedia
Horn clause
In mathematical logic and logic programming, a Horn clause is a logical formula of a particular rule-like form which gives it useful properties for use in logic programming, formal specification, and model theory. Horn clauses are named for the logician Alfred Horn, who first pointed out their significance in 1951.
