theory IntEx2

imports "../QuotMain"

(*uses

  ("Tools/numeral.ML")

  ("Tools/numeral_syntax.ML")

  ("Tools/int_arith.ML")*)

begin

fun

  intrel :: "(nat \<times> nat) \<Rightarrow> (nat \<times> nat) \<Rightarrow> bool" (infix "\<approx>" 50)

where

  "intrel (x, y) (u, v) = (x + v = u + y)"

quotient int = "nat \<times> nat" / intrel

  apply(unfold equivp_def)

  apply(auto simp add: mem_def expand_fun_eq)

  done

instantiation int :: "{zero, one, plus, minus, uminus, times, ord, abs, sgn}"

begin

where

where

fun

  plus_raw :: "(nat \<times> nat) \<Rightarrow> (nat \<times> nat) \<Rightarrow> (nat \<times> nat)"

where

  "plus_raw (x, y) (u, v) = (x + u, y + v)"

where

fun

  minus_raw :: "(nat \<times> nat) \<Rightarrow> (nat \<times> nat)"

where

  "minus_raw (x, y) = (y, x)"

quotient_def

where

definition

fun

where

where

fun

where

where

definition

  less_int_def [code del]: "(z\<Colon>int) < w = (z \<le> w \<and> z \<noteq> w)"

definition

definition

instance ..

end

lemma plus_raw_rsp[quot_respect]:

  shows "(op \<approx> ===> op \<approx> ===> op \<approx>) plus_raw plus_raw"

by auto

lemma minus_raw_rsp[quot_respect]:

  shows "(op \<approx> ===> op \<approx>) minus_raw minus_raw"

  by auto

lemma mult_raw_rsp[quot_respect]:

apply(auto)

apply(simp add: algebra_simps)

sorry

by auto

lemma plus_assoc_raw:

  shows "plus_raw (plus_raw i j) k \<approx> plus_raw i (plus_raw j k)"

by (cases i, cases j, cases k) (simp)

lemma plus_sym_raw:

  shows "plus_raw i j \<approx> plus_raw j i"

by (cases i, cases j) (simp)

lemma plus_zero_raw:

  shows "plus_raw  (0, 0) i \<approx> i"

by (cases i) (simp)

lemma plus_minus_zero_raw:

  shows "plus_raw (minus_raw i) i \<approx> (0, 0)"

by (cases i) (simp)

by (cases i, cases j, cases k) 

   (simp add: algebra_simps)

by (cases i, cases j) (simp add: algebra_simps)

by (cases i) (simp)

by (cases i, cases j, cases k) 

   (simp add: algebra_simps)

lemma one_zero_distinct:

  shows "\<not> (0, 0) \<approx> ((1::nat), (0::nat))"

  by simp

text{*The integers form a @{text comm_ring_1}*}

instance int :: comm_ring_1

proof

  fix i j k :: int

  show "(i + j) + k = i + (j + k)"

  show "i + j = j + i" 

    by (lifting plus_sym_raw)

  show "0 + i = (i::int)"

    by (lifting plus_zero_raw)

  show "- i + i = 0"

    by (lifting plus_minus_zero_raw)

  show "i - j = i + - j"

  show "(i * j) * k = i * (j * k)"

  show "i * j = j * i"

  show "1 * i = i"

  show "(i + j) * k = i * k + j * k"

  show "0 \<noteq> (1::int)"

    by (lifting one_zero_distinct)

qed

term of_nat

thm of_nat_def

lemma int_def: "of_nat m = ABS_int (m, 0)"

apply(simp)

oops

lemma le_antisym_raw:

by (cases i, cases j) (simp)

lemma le_refl_raw:

by (cases i) (simp)

lemma le_trans_raw:

by (cases i, cases j, cases k) (simp)

lemma le_cases_raw:

by (cases i, cases j) 

   (simp add: linorder_linear)

instance int :: linorder

proof

  fix i j k :: int

  show antisym: "i \<le> j \<Longrightarrow> j \<le> i \<Longrightarrow> i = j"

    by (lifting le_antisym_raw)

  show "(i < j) = (i \<le> j \<and> \<not> j \<le> i)"

    by (auto simp add: less_int_def dest: antisym) 

  show "i \<le> i"

    by (lifting le_refl_raw)

  show "i \<le> j \<Longrightarrow> j \<le> k \<Longrightarrow> i \<le> k"

    by (lifting le_trans_raw)

  show "i \<le> j \<or> j \<le> i"

    by (lifting le_cases_raw)

qed

instantiation int :: distrib_lattice

begin

definition

  "(inf \<Colon> int \<Rightarrow> int \<Rightarrow> int) = min"

definition

  "(sup \<Colon> int \<Rightarrow> int \<Rightarrow> int) = max"

instance

  by intro_classes

    (auto simp add: inf_int_def sup_int_def min_max.sup_inf_distrib1)

end

lemma le_plus_raw:

by (cases i, cases j, cases k) (simp)

instance int :: pordered_cancel_ab_semigroup_add

proof

  fix i j k :: int

  show "i \<le> j \<Longrightarrow> k + i \<le> k + j"

    by (lifting le_plus_raw)

qed

lemma test:

apply(cases i, cases j, cases k)

apply(auto simp add: algebra_simps)

sorry

text{*The integers form an ordered integral domain*}

instance int :: ordered_idom

proof

  fix i j k :: int

  show "i < j \<Longrightarrow> 0 < k \<Longrightarrow> k * i < k * j"

    by (lifting test)

  show "\<bar>i\<bar> = (if i < 0 then -i else i)"

  show "sgn (i\<Colon>int) = (if i=0 then 0 else if 0<i then 1 else - 1)"

qed

instance int :: lordered_ring

proof  

  fix k :: int

  show "abs k = sup k (- k)"

qed

lemmas int_distrib =

  left_distrib [of "z1::int" "z2" "w", standard]

  right_distrib [of "w::int" "z1" "z2", standard]

  left_diff_distrib [of "z1::int" "z2" "w", standard]

  right_diff_distrib [of "w::int" "z1" "z2", standard]

subsection {* Embedding of the Integers into any @{text ring_1}: @{text of_int}*}

(*

context ring_1

begin

definition 

  of_int :: "int \<Rightarrow> 'a" 

where

  "of_int 

*)

subsection {* Binary representation *}

text {*

  This formalization defines binary arithmetic in terms of the integers

  rather than using a datatype. This avoids multiple representations (leading

  zeroes, etc.)  See @{text "ZF/Tools/twos-compl.ML"}, function @{text

  int_of_binary}, for the numerical interpretation.

  The representation expects that @{text "(m mod 2)"} is 0 or 1,

  even if m is negative;

  For instance, @{text "-5 div 2 = -3"} and @{text "-5 mod 2 = 1"}; thus

  @{text "-5 = (-3)*2 + 1"}.

  This two's complement binary representation derives from the paper 

  "An Efficient Representation of Arithmetic for Term Rewriting" by

  Dave Cohen and Phil Watson, Rewriting Techniques and Applications,

  Springer LNCS 488 (240-251), 1991.

*}

subsubsection {* The constructors @{term Bit0}, @{term Bit1}, @{term Pls} and @{term Min} *}

definition

  Pls :: int where

  [code del]: "Pls = 0"

definition

  Min :: int where

  [code del]: "Min = - 1"

definition

  Bit0 :: "int \<Rightarrow> int" where

  [code del]: "Bit0 k = k + k"

definition

  Bit1 :: "int \<Rightarrow> int" where

  [code del]: "Bit1 k = 1 + k + k"

class number = -- {* for numeric types: nat, int, real, \dots *}

  fixes number_of :: "int \<Rightarrow> 'a"

(*use "~~/src/HOL/Tools/numeral.ML"

syntax

  "_Numeral" :: "num_const \<Rightarrow> 'a"    ("_")

use "~~/src/HOL/Tools/numeral_syntax.ML"

setup NumeralSyntax.setup

abbreviation

  "Numeral0 \<equiv> number_of Pls"

abbreviation

  "Numeral1 \<equiv> number_of (Bit1 Pls)"

lemma Let_number_of [simp]: "Let (number_of v) f = f (number_of v)"

  -- {* Unfold all @{text let}s involving constants *}

  unfolding Let_def ..

definition

  succ :: "int \<Rightarrow> int" where

  [code del]: "succ k = k + 1"

definition

  pred :: "int \<Rightarrow> int" where

  [code del]: "pred k = k - 1"

lemmas

  max_number_of [simp] = max_def

    [of "number_of u" "number_of v", standard, simp]

and

  min_number_of [simp] = min_def 

    [of "number_of u" "number_of v", standard, simp]

  -- {* unfolding @{text minx} and @{text max} on numerals *}

lemmas numeral_simps = 

  succ_def pred_def Pls_def Min_def Bit0_def Bit1_def

text {* Removal of leading zeroes *}

lemma Bit0_Pls [simp, code_post]:

  "Bit0 Pls = Pls"

  unfolding numeral_simps by simp

lemma Bit1_Min [simp, code_post]:

  "Bit1 Min = Min"

  unfolding numeral_simps by simp

lemmas normalize_bin_simps =

  Bit0_Pls Bit1_Min

*)