doc-src/TutorialI/Types/numerics.tex
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   395 reproducing it here, we refer you to the theory \texttt{RComplete} in
   395 reproducing it here, we refer you to the theory \texttt{RComplete} in
   396 directory \texttt{Real}.
   396 directory \texttt{Real}.
   397 Density, however, is trivial to express:
   397 Density, however, is trivial to express:
   398 \begin{isabelle}
   398 \begin{isabelle}
   399 x\ <\ y\ \isasymLongrightarrow \ \isasymexists r.\ x\ <\ r\ \isasymand \ r\ <\ y%
   399 x\ <\ y\ \isasymLongrightarrow \ \isasymexists r.\ x\ <\ r\ \isasymand \ r\ <\ y%
   400 \rulename{real_dense}
   400 \rulename{dense}
   401 \end{isabelle}
   401 \end{isabelle}
   402 
   402 
   403 Here is a selection of rules about the division operator.  The following
   403 Here is a selection of rules about the division operator.  The following
   404 are installed as default simplification rules in order to express
   404 are installed as default simplification rules in order to express
   405 combinations of products and quotients as rational expressions:
   405 combinations of products and quotients as rational expressions:
   415 \end{isabelle}
   415 \end{isabelle}
   416 
   416 
   417 Signs are extracted from quotients in the hope that complementary terms can
   417 Signs are extracted from quotients in the hope that complementary terms can
   418 then be cancelled:
   418 then be cancelled:
   419 \begin{isabelle}
   419 \begin{isabelle}
   420 -\ x\ /\ y\ =\ -\ (x\ /\ y)
   420 -\ (a\ /\ b)\ =\ -\ a\ /\ b
   421 \rulename{real_minus_divide_eq}\isanewline
   421 \rulename{minus_divide_left}\isanewline
   422 x\ /\ -\ y\ =\ -\ (x\ /\ y)
   422 -\ (a\ /\ b)\ =\ a\ /\ -\ b
   423 \rulename{real_divide_minus_eq}
   423 \rulename{minus_divide_right}
   424 \end{isabelle}
   424 \end{isabelle}
   425 
   425 
   426 The following distributive law is available, but it is not installed as a
   426 The following distributive law is available, but it is not installed as a
   427 simplification rule.
   427 simplification rule.
   428 \begin{isabelle}
   428 \begin{isabelle}
   429 (x\ +\ y)\ /\ z\ =\ x\ /\ z\ +\ y\ /\ z%
   429 (a\ +\ b)\ /\ c\ =\ a\ /\ c\ +\ b\ /\ c%
   430 \rulename{real_add_divide_distrib}
   430 \rulename{add_divide_distrib}
   431 \end{isabelle}
   431 \end{isabelle}
   432 
   432 
   433 As with the other numeric types, the simplifier can sort the operands of
   433 As with the other numeric types, the simplifier can sort the operands of
   434 addition and multiplication.  The name \isa{real_add_ac} refers to the
   434 addition and multiplication.  The name \isa{real_add_ac} refers to the
   435 associativity and commutativity theorems for addition, while similarly
   435 associativity and commutativity theorems for addition, while similarly