author wenzelm Tue Feb 21 16:28:18 2012 +0100 (2012-02-21) changeset 46573 8c4c5c8dcf7a parent 46572 3074685ab7ed child 46574 41701fce8ac7
misc tuning;
more indentation;
 src/HOL/Library/Float.thy file | annotate | diff | revisions src/HOL/Library/Fraction_Field.thy file | annotate | diff | revisions
```     1.1 --- a/src/HOL/Library/Float.thy	Tue Feb 21 16:04:58 2012 +0100
1.2 +++ b/src/HOL/Library/Float.thy	Tue Feb 21 16:28:18 2012 +0100
1.3 @@ -9,8 +9,7 @@
1.4  imports Complex_Main Lattice_Algebras
1.5  begin
1.6
1.7 -definition
1.8 -  pow2 :: "int \<Rightarrow> real" where
1.9 +definition pow2 :: "int \<Rightarrow> real" where
1.10    [simp]: "pow2 a = (if (0 <= a) then (2^(nat a)) else (inverse (2^(nat (-a)))))"
1.11
1.12  datatype float = Float int int
1.13 @@ -30,17 +29,20 @@
1.14  primrec scale :: "float \<Rightarrow> int" where
1.15    "scale (Float a b) = b"
1.16
1.17 -instantiation float :: zero begin
1.18 +instantiation float :: zero
1.19 +begin
1.20  definition zero_float where "0 = Float 0 0"
1.21  instance ..
1.22  end
1.23
1.24 -instantiation float :: one begin
1.25 +instantiation float :: one
1.26 +begin
1.27  definition one_float where "1 = Float 1 0"
1.28  instance ..
1.29  end
1.30
1.31 -instantiation float :: number begin
1.32 +instantiation float :: number
1.33 +begin
1.34  definition number_of_float where "number_of n = Float n 0"
1.35  instance ..
1.36  end
1.37 @@ -124,13 +126,13 @@
1.38    by (auto simp add: pow2_def)
1.39
1.40  lemma pow2_int: "pow2 (int c) = 2^c"
1.42 +  by (simp add: pow2_def)
1.43
1.44 -lemma zero_less_pow2[simp]:
1.45 -  "0 < pow2 x"
1.46 +lemma zero_less_pow2[simp]: "0 < pow2 x"
1.48
1.49 -lemma normfloat_imp_odd_or_zero: "normfloat f = Float a b \<Longrightarrow> odd a \<or> (a = 0 \<and> b = 0)"
1.50 +lemma normfloat_imp_odd_or_zero:
1.51 +  "normfloat f = Float a b \<Longrightarrow> odd a \<or> (a = 0 \<and> b = 0)"
1.52  proof (induct f rule: normfloat.induct)
1.53    case (1 u v)
1.54    from 1 have ab: "normfloat (Float u v) = Float a b" by auto
1.55 @@ -169,7 +171,7 @@
1.56
1.57  lemma float_eq_odd_helper:
1.58    assumes odd: "odd a'"
1.59 -  and floateq: "real (Float a b) = real (Float a' b')"
1.60 +    and floateq: "real (Float a b) = real (Float a' b')"
1.61    shows "b \<le> b'"
1.62  proof -
1.63    from odd have "a' \<noteq> 0" by auto
1.64 @@ -191,8 +193,8 @@
1.65
1.66  lemma float_eq_odd:
1.67    assumes odd1: "odd a"
1.68 -  and odd2: "odd a'"
1.69 -  and floateq: "real (Float a b) = real (Float a' b')"
1.70 +    and odd2: "odd a'"
1.71 +    and floateq: "real (Float a b) = real (Float a' b')"
1.72    shows "a = a' \<and> b = b'"
1.73  proof -
1.74    from
1.75 @@ -216,7 +218,7 @@
1.76    have ab': "odd a' \<or> (a' = 0 \<and> b' = 0)" by (rule normfloat_imp_odd_or_zero[OF normg])
1.77    {
1.78      assume odd: "odd a"
1.79 -    then have "a \<noteq> 0" by (simp add: even_def, arith)
1.80 +    then have "a \<noteq> 0" by (simp add: even_def) arith
1.81      with float_eq have "a' \<noteq> 0" by auto
1.82      with ab' have "odd a'" by simp
1.83      from odd this float_eq have "a = a' \<and> b = b'" by (rule float_eq_odd)
1.84 @@ -236,7 +238,8 @@
1.85      done
1.86  qed
1.87
1.88 -instantiation float :: plus begin
1.89 +instantiation float :: plus
1.90 +begin
1.91  fun plus_float where
1.92  [simp del]: "(Float a_m a_e) + (Float b_m b_e) =
1.93       (if a_e \<le> b_e then Float (a_m + b_m * 2^(nat(b_e - a_e))) a_e
1.94 @@ -244,17 +247,20 @@
1.95  instance ..
1.96  end
1.97
1.98 -instantiation float :: uminus begin
1.99 +instantiation float :: uminus
1.100 +begin
1.101  primrec uminus_float where [simp del]: "uminus_float (Float m e) = Float (-m) e"
1.102  instance ..
1.103  end
1.104
1.105 -instantiation float :: minus begin
1.106 -definition minus_float where [simp del]: "(z::float) - w = z + (- w)"
1.107 +instantiation float :: minus
1.108 +begin
1.109 +definition minus_float where "(z::float) - w = z + (- w)"
1.110  instance ..
1.111  end
1.112
1.113 -instantiation float :: times begin
1.114 +instantiation float :: times
1.115 +begin
1.116  fun times_float where [simp del]: "(Float a_m a_e) * (Float b_m b_e) = Float (a_m * b_m) (a_e + b_e)"
1.117  instance ..
1.118  end
1.119 @@ -265,7 +271,8 @@
1.120  primrec float_nprt :: "float \<Rightarrow> float" where
1.121    "float_nprt (Float a e) = (if 0 <= a then 0 else (Float a e))"
1.122
1.123 -instantiation float :: ord begin
1.124 +instantiation float :: ord
1.125 +begin
1.126  definition le_float_def: "z \<le> (w :: float) \<equiv> real z \<le> real w"
1.127  definition less_float_def: "z < (w :: float) \<equiv> real z < real w"
1.128  instance ..
1.129 @@ -276,7 +283,7 @@
1.131
1.132  lemma real_of_float_minus[simp]: "real (- a) = - real (a :: float)"
1.133 -  by (cases a) (simp add: uminus_float.simps)
1.134 +  by (cases a) simp
1.135
1.136  lemma real_of_float_sub[simp]: "real (a - b) = real a - real (b :: float)"
1.137    by (cases a, cases b) (simp add: minus_float_def)
1.138 @@ -285,7 +292,7 @@
1.140
1.141  lemma real_of_float_0[simp]: "real (0 :: float) = 0"
1.142 -  by (auto simp add: zero_float_def float_zero)
1.143 +  by (auto simp add: zero_float_def)
1.144
1.145  lemma real_of_float_1[simp]: "real (1 :: float) = 1"
1.146    by (auto simp add: one_float_def)
1.147 @@ -1161,16 +1168,20 @@
1.148  qed
1.149
1.150  definition lb_mult :: "nat \<Rightarrow> float \<Rightarrow> float \<Rightarrow> float" where
1.151 -"lb_mult prec x y = (case normfloat (x * y) of Float m e \<Rightarrow> let
1.152 -    l = bitlen m - int prec
1.153 -  in if l > 0 then Float (m div (2^nat l)) (e + l)
1.154 -              else Float m e)"
1.155 +  "lb_mult prec x y =
1.156 +    (case normfloat (x * y) of Float m e \<Rightarrow>
1.157 +      let
1.158 +        l = bitlen m - int prec
1.159 +      in if l > 0 then Float (m div (2^nat l)) (e + l)
1.160 +                  else Float m e)"
1.161
1.162  definition ub_mult :: "nat \<Rightarrow> float \<Rightarrow> float \<Rightarrow> float" where
1.163 -"ub_mult prec x y = (case normfloat (x * y) of Float m e \<Rightarrow> let
1.164 -    l = bitlen m - int prec
1.165 -  in if l > 0 then Float (m div (2^nat l) + 1) (e + l)
1.166 -              else Float m e)"
1.167 +  "ub_mult prec x y =
1.168 +    (case normfloat (x * y) of Float m e \<Rightarrow>
1.169 +      let
1.170 +        l = bitlen m - int prec
1.171 +      in if l > 0 then Float (m div (2^nat l) + 1) (e + l)
1.172 +                  else Float m e)"
1.173
1.174  lemma lb_mult: "real (lb_mult prec x y) \<le> real (x * y)"
1.175  proof (cases "normfloat (x * y)")
1.176 @@ -1225,7 +1236,8 @@
1.177  primrec float_abs :: "float \<Rightarrow> float" where
1.178    "float_abs (Float m e) = Float \<bar>m\<bar> e"
1.179
1.180 -instantiation float :: abs begin
1.181 +instantiation float :: abs
1.182 +begin
1.183  definition abs_float_def: "\<bar>x\<bar> = float_abs x"
1.184  instance ..
1.185  end
1.186 @@ -1290,10 +1302,10 @@
1.187  declare ceiling_fl.simps[simp del]
1.188
1.189  definition lb_mod :: "nat \<Rightarrow> float \<Rightarrow> float \<Rightarrow> float \<Rightarrow> float" where
1.190 -"lb_mod prec x ub lb = x - ceiling_fl (float_divr prec x lb) * ub"
1.191 +  "lb_mod prec x ub lb = x - ceiling_fl (float_divr prec x lb) * ub"
1.192
1.193  definition ub_mod :: "nat \<Rightarrow> float \<Rightarrow> float \<Rightarrow> float \<Rightarrow> float" where
1.194 -"ub_mod prec x ub lb = x - floor_fl (float_divl prec x ub) * lb"
1.195 +  "ub_mod prec x ub lb = x - floor_fl (float_divl prec x ub) * lb"
1.196
1.197  lemma lb_mod: fixes k :: int assumes "0 \<le> real x" and "real k * y \<le> real x" (is "?k * y \<le> ?x")
1.198    assumes "0 < real lb" "real lb \<le> y" (is "?lb \<le> y") "y \<le> real ub" (is "y \<le> ?ub")
1.199 @@ -1307,7 +1319,9 @@
1.200    finally show ?thesis unfolding lb_mod_def real_of_float_sub real_of_float_mult by auto
1.201  qed
1.202
1.203 -lemma ub_mod: fixes k :: int and x :: float assumes "0 \<le> real x" and "real x \<le> real k * y" (is "?x \<le> ?k * y")
1.204 +lemma ub_mod:
1.205 +  fixes k :: int and x :: float
1.206 +  assumes "0 \<le> real x" and "real x \<le> real k * y" (is "?x \<le> ?k * y")
1.207    assumes "0 < real lb" "real lb \<le> y" (is "?lb \<le> y") "y \<le> real ub" (is "y \<le> ?ub")
1.208    shows "?x - ?k * y \<le> real (ub_mod prec x ub lb)"
1.209  proof -
```
```     2.1 --- a/src/HOL/Library/Fraction_Field.thy	Tue Feb 21 16:04:58 2012 +0100
2.2 +++ b/src/HOL/Library/Fraction_Field.thy	Tue Feb 21 16:28:18 2012 +0100
2.3 @@ -2,8 +2,8 @@
2.4      Author:     Amine Chaieb, University of Cambridge
2.5  *)
2.6
2.7 -header{* A formalization of the fraction field of any integral domain
2.8 -         A generalization of Rat.thy from int to any integral domain *}
2.9 +header{* A formalization of the fraction field of any integral domain;
2.10 +         generalization of theory Rat from int to any integral domain *}
2.11
2.12  theory Fraction_Field
2.13  imports Main
2.14 @@ -14,7 +14,7 @@
2.15  subsubsection {* Construction of the type of fractions *}
2.16
2.17  definition fractrel :: "(('a::idom * 'a ) * ('a * 'a)) set" where
2.18 -  "fractrel == {(x, y). snd x \<noteq> 0 \<and> snd y \<noteq> 0 \<and> fst x * snd y = fst y * snd x}"
2.19 +  "fractrel = {(x, y). snd x \<noteq> 0 \<and> snd y \<noteq> 0 \<and> fst x * snd y = fst y * snd x}"
2.20
2.21  lemma fractrel_iff [simp]:
2.22    "(x, y) \<in> fractrel \<longleftrightarrow> snd x \<noteq> 0 \<and> snd y \<noteq> 0 \<and> fst x * snd y = fst y * snd x"
2.23 @@ -70,8 +70,7 @@
2.24
2.25  subsubsection {* Representation and basic operations *}
2.26
2.27 -definition
2.28 -  Fract :: "'a::idom \<Rightarrow> 'a \<Rightarrow> 'a fract" where
2.29 +definition Fract :: "'a::idom \<Rightarrow> 'a \<Rightarrow> 'a fract" where
2.30    "Fract a b = Abs_fract (fractrel `` {if b = 0 then (0, 1) else (a, b)})"
2.31
2.32  code_datatype Fract
2.33 @@ -95,14 +94,11 @@
2.34  instantiation fract :: (idom) "{comm_ring_1, power}"
2.35  begin
2.36
2.37 -definition
2.38 -  Zero_fract_def [code_unfold]: "0 = Fract 0 1"
2.39 +definition Zero_fract_def [code_unfold]: "0 = Fract 0 1"
2.40
2.41 -definition
2.42 -  One_fract_def [code_unfold]: "1 = Fract 1 1"
2.43 +definition One_fract_def [code_unfold]: "1 = Fract 1 1"
2.44
2.45 -definition
2.48    "q + r = Abs_fract (\<Union>x \<in> Rep_fract q. \<Union>y \<in> Rep_fract r.
2.49      fractrel `` {(fst x * snd y + fst y * snd x, snd x * snd y)})"
2.50
2.51 @@ -117,8 +113,7 @@
2.53  qed
2.54
2.55 -definition
2.56 -  minus_fract_def:
2.57 +definition minus_fract_def:
2.58    "- q = Abs_fract (\<Union>x \<in> Rep_fract q. fractrel `` {(- fst x, snd x)})"
2.59
2.60  lemma minus_fract [simp, code]: "- Fract a b = Fract (- a) (b::'a::idom)"
2.61 @@ -131,16 +126,14 @@
2.62  lemma minus_fract_cancel [simp]: "Fract (- a) (- b) = Fract a b"
2.63    by (cases "b = 0") (simp_all add: eq_fract)
2.64
2.65 -definition
2.66 -  diff_fract_def: "q - r = q + - (r::'a fract)"
2.67 +definition diff_fract_def: "q - r = q + - (r::'a fract)"
2.68
2.69  lemma diff_fract [simp]:
2.70    assumes "b \<noteq> 0" and "d \<noteq> 0"
2.71    shows "Fract a b - Fract c d = Fract (a * d - c * b) (b * d)"
2.72    using assms by (simp add: diff_fract_def diff_minus)
2.73
2.74 -definition
2.75 -  mult_fract_def:
2.76 +definition mult_fract_def:
2.77    "q * r = Abs_fract (\<Union>x \<in> Rep_fract q. \<Union>y \<in> Rep_fract r.
2.78      fractrel``{(fst x * fst y, snd x * snd y)})"
2.79
2.80 @@ -238,8 +231,7 @@
2.81  instantiation fract :: (idom) field_inverse_zero
2.82  begin
2.83
2.84 -definition
2.85 -  inverse_fract_def:
2.86 +definition inverse_fract_def:
2.87    "inverse q = Abs_fract (\<Union>x \<in> Rep_fract q.
2.88       fractrel `` {if fst x = 0 then (0, 1) else (snd x, fst x)})"
2.89
2.90 @@ -252,8 +244,7 @@
2.91    then show ?thesis by (simp add: Fract_def inverse_fract_def UN_fractrel)
2.92  qed
2.93
2.94 -definition
2.95 -  divide_fract_def: "q / r = q * inverse (r:: 'a fract)"
2.96 +definition divide_fract_def: "q / r = q * inverse (r:: 'a fract)"
2.97
2.98  lemma divide_fract [simp]: "Fract a b / Fract c d = Fract (a * d) (b * c)"
2.100 @@ -261,14 +252,15 @@
2.101  instance proof
2.102    fix q :: "'a fract"
2.103    assume "q \<noteq> 0"
2.104 -  then show "inverse q * q = 1" apply (cases q rule: Fract_cases_nonzero)
2.105 -    by (simp_all add: mult_fract  inverse_fract fract_expand eq_fract mult_commute)
2.106 +  then show "inverse q * q = 1"
2.107 +    by (cases q rule: Fract_cases_nonzero)
2.108 +      (simp_all add: fract_expand eq_fract mult_commute)
2.109  next
2.110    fix q r :: "'a fract"
2.111    show "q / r = q * inverse r" by (simp add: divide_fract_def)
2.112  next
2.113 -  show "inverse 0 = (0:: 'a fract)" by (simp add: fract_expand)
2.115 +  show "inverse 0 = (0:: 'a fract)"
2.117  qed
2.118
2.119  end
2.120 @@ -292,7 +284,7 @@
2.121      have "?le a b c d = ?le (a * x) (b * x) c d"
2.122      proof -
2.123        from x have "0 < x * x" by (auto simp add: zero_less_mult_iff)
2.124 -      hence "?le a b c d =
2.125 +      then have "?le a b c d =
2.126            ((a * d) * (b * d) * (x * x) \<le> (c * b) * (b * d) * (x * x))"
2.128        also have "... = ?le (a * x) (b * x) c d"
2.129 @@ -304,7 +296,7 @@
2.130    let ?D = "b * d" and ?D' = "b' * d'"
2.131    from neq have D: "?D \<noteq> 0" by simp
2.132    from neq have "?D' \<noteq> 0" by simp
2.133 -  hence "?le a b c d = ?le (a * ?D') (b * ?D') c d"
2.134 +  then have "?le a b c d = ?le (a * ?D') (b * ?D') c d"
2.135      by (rule le_factor)
2.136    also have "... = ((a * b') * ?D * ?D' * d * d' \<le> (c * d') * ?D * ?D' * b * b')"
2.138 @@ -320,13 +312,11 @@
2.139  instantiation fract :: (linordered_idom) linorder
2.140  begin
2.141
2.142 -definition
2.143 -  le_fract_def:
2.144 +definition le_fract_def:
2.145     "q \<le> r \<longleftrightarrow> the_elem (\<Union>x \<in> Rep_fract q. \<Union>y \<in> Rep_fract r.
2.146        {(fst x * snd y)*(snd x * snd y) \<le> (fst y * snd x)*(snd x * snd y)})"
2.147
2.148 -definition
2.149 -  less_fract_def: "z < (w::'a fract) \<longleftrightarrow> z \<le> w \<and> \<not> w \<le> z"
2.150 +definition less_fract_def: "z < (w::'a fract) \<longleftrightarrow> z \<le> w \<and> \<not> w \<le> z"
2.151
2.152  lemma le_fract [simp]:
2.153    assumes "b \<noteq> 0" and "d \<noteq> 0"
2.154 @@ -409,28 +399,25 @@
2.155  instantiation fract :: (linordered_idom) "{distrib_lattice, abs_if, sgn_if}"
2.156  begin
2.157
2.158 -definition
2.159 -  abs_fract_def: "\<bar>q\<bar> = (if q < 0 then -q else (q::'a fract))"
2.160 +definition abs_fract_def: "\<bar>q\<bar> = (if q < 0 then -q else (q::'a fract))"
2.161
2.162 -definition
2.163 -  sgn_fract_def:
2.164 -    "sgn (q::'a fract) = (if q=0 then 0 else if 0<q then 1 else - 1)"
2.165 +definition sgn_fract_def:
2.166 +  "sgn (q::'a fract) = (if q=0 then 0 else if 0<q then 1 else - 1)"
2.167
2.168  theorem abs_fract [simp]: "\<bar>Fract a b\<bar> = Fract \<bar>a\<bar> \<bar>b\<bar>"
2.169    by (auto simp add: abs_fract_def Zero_fract_def le_less
2.170        eq_fract zero_less_mult_iff mult_less_0_iff split: abs_split)
2.171
2.172 -definition
2.173 -  inf_fract_def:
2.174 -    "(inf \<Colon> 'a fract \<Rightarrow> 'a fract \<Rightarrow> 'a fract) = min"
2.175 +definition inf_fract_def:
2.176 +  "(inf \<Colon> 'a fract \<Rightarrow> 'a fract \<Rightarrow> 'a fract) = min"
2.177
2.178 -definition
2.179 -  sup_fract_def:
2.180 -    "(sup \<Colon> 'a fract \<Rightarrow> 'a fract \<Rightarrow> 'a fract) = max"
2.181 +definition sup_fract_def:
2.182 +  "(sup \<Colon> 'a fract \<Rightarrow> 'a fract \<Rightarrow> 'a fract) = max"
2.183
2.184 -instance by intro_classes
2.185 -  (auto simp add: abs_fract_def sgn_fract_def
2.186 -    min_max.sup_inf_distrib1 inf_fract_def sup_fract_def)
2.187 +instance
2.188 +  by intro_classes
2.189 +    (auto simp add: abs_fract_def sgn_fract_def
2.190 +      min_max.sup_inf_distrib1 inf_fract_def sup_fract_def)
2.191
2.192  end
2.193
2.194 @@ -485,8 +472,8 @@
2.195    proof -
2.196      fix a::'a and b::'a
2.197      assume b: "b < 0"
2.198 -    hence "0 < -b" by simp
2.199 -    hence "P (Fract (-a) (-b))" by (rule step)
2.200 +    then have "0 < -b" by simp
2.201 +    then have "P (Fract (-a) (-b))" by (rule step)
2.202      thus "P (Fract a b)" by (simp add: order_less_imp_not_eq [OF b])
2.203    qed
2.204    case (Fract a b)
```