equal
deleted
inserted
replaced
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 |