# HG changeset patch # User paulson # Date 986803919 -7200 # Node ID 81fe09ce5fc97a98e85d40839b69bfd34e672965 # Parent 61b21aacf04af309f003e432d40dc6b50f30f2f5 lexicographic product of two relations: updated HOL.tex Also automatic updates by xemacs diff -r 61b21aacf04a -r 81fe09ce5fc9 doc-src/HOL/HOL.tex --- a/doc-src/HOL/HOL.tex Mon Apr 09 10:10:21 2001 +0200 +++ b/doc-src/HOL/HOL.tex Mon Apr 09 10:11:59 2001 +0200 @@ -2711,7 +2711,8 @@ is less than $f(y)$ according to~$R$, which must itself be a well-founded relation. -\item $R@1\texttt{**}R@2$ is the lexicographic product of two relations. It +\item $R@1\texttt{<*lex*>}R@2$ is the lexicographic product of two relations. + It is a relation on pairs and satisfies $(x@1,x@2)\prec(y@1,y@2)$ if and only if $x@1$ is less than $y@1$ according to~$R@1$ or $x@1=y@1$ and $x@2$ @@ -2950,23 +2951,23 @@ monotonicity of inductive definitions whose introduction rules have premises involving terms such as $t\in M(R@i)$. \item Monotonicity theorems for logical operators, which are of the general form - $\List{\cdots \rightarrow \cdots;~\ldots;~\cdots \rightarrow \cdots} \Imp - \cdots \rightarrow \cdots$. - For example, in the case of the operator $\vee$, the corresponding theorem is + $\List{\cdots \to \cdots;~\ldots;~\cdots \to \cdots} \Imp + \cdots \to \cdots$. + For example, in the case of the operator $\lor$, the corresponding theorem is \[ - \infer{P@1 \vee P@2 \rightarrow Q@1 \vee Q@2} - {P@1 \rightarrow Q@1 & P@2 \rightarrow Q@2} + \infer{P@1 \lor P@2 \to Q@1 \lor Q@2} + {P@1 \to Q@1 & P@2 \to Q@2} \] \item De Morgan style equations for reasoning about the ``polarity'' of expressions, e.g. \[ - (\neg \neg P) ~=~ P \qquad\qquad - (\neg (P \wedge Q)) ~=~ (\neg P \vee \neg Q) + (\lnot \lnot P) ~=~ P \qquad\qquad + (\lnot (P \land Q)) ~=~ (\lnot P \lor \lnot Q) \] \item Equations for reducing complex operators to more primitive ones whose monotonicity can easily be proved, e.g. \[ - (P \rightarrow Q) ~=~ (\neg P \vee Q) \qquad\qquad - \mathtt{Ball}~A~P ~\equiv~ \forall x.~x \in A \rightarrow P~x + (P \to Q) ~=~ (\lnot P \lor Q) \qquad\qquad + \mathtt{Ball}~A~P ~\equiv~ \forall x.~x \in A \to P~x \] \end{itemize}