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Specific Treatment of Binary Relations

Saturate attempts to automatically recognize certain properties of binary relations and then specializes the chaining-based inference rules accordingly. Also, the simplification module will know about these properties. The system recognizes and treats in a specific manner
transitivity
or, more generally, certain collections of composition laws of the form

\begin{displaymath}
p(X,Y), q(Y,Z) \to r(X,Z),
\end{displaymath}

for binary relations $p$, $q$, and $r$;

totality laws
of the form

\begin{displaymath}
\to p(X,Y), p(Y,X), X=Y  ;
\end{displaymath}

reflexivity and irreflexivity laws
of the form

\begin{displaymath}
\to p(X,X)
\end{displaymath}

or

\begin{displaymath}
p(X,X) \to  ;
\end{displaymath}

monotonicity laws
of the form

\begin{displaymath}
p(X,Y) \to p(f(\ldots X \ldots),f(\ldots Y \ldots))  ;
\end{displaymath}

anti-monotonicity laws
of the form

\begin{displaymath}
p(X,Y) \to p(f(\ldots Y \ldots),f(\ldots X \ldots))  ;
\end{displaymath}

symmetry laws
of the form

\begin{displaymath}
\to p(X,Y) , p(Y,X)  ;
\end{displaymath}

density laws
of the form

\begin{displaymath}
p(X,Y) \to p(X,d(X,Y)) \wedge p(d(X,Y),Y)
\end{displaymath}

(written as two clauses); and

laws about the absense of endpoints
of the form

\begin{displaymath}
\to p(X,f(X))
\end{displaymath}

or

\begin{displaymath}
\to p(g(X),X).
\end{displaymath}

Interesting types of binary relations with such properties include equivalences, equality (congruences) and orderings.


next up previous contents
Next: Redundancy Up: Inference System Previous: Modal Logics   Contents
Harald Ganzinger 2002-12-04

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