src/HOL/Quickcheck_Narrowing.thy
changeset 51143 0a2371e7ced3
parent 50046 0051dc4f301f
child 52435 6646bb548c6b
--- a/src/HOL/Quickcheck_Narrowing.thy	Fri Feb 15 08:31:30 2013 +0100
+++ b/src/HOL/Quickcheck_Narrowing.thy	Fri Feb 15 08:31:31 2013 +0100
@@ -9,188 +9,26 @@
 
 subsection {* Counterexample generator *}
 
-text {* We create a new target for the necessary code generation setup. *}
+subsubsection {* Code generation setup *}
 
 setup {* Code_Target.extend_target ("Haskell_Quickcheck", (Code_Haskell.target, K I)) *}
 
-subsubsection {* Code generation setup *}
-
 code_type typerep
   (Haskell_Quickcheck "Typerep")
 
 code_const Typerep.Typerep
   (Haskell_Quickcheck "Typerep")
 
+code_type integer
+  (Haskell_Quickcheck "Prelude.Int")
+
 code_reserved Haskell_Quickcheck Typerep
 
-subsubsection {* Type @{text "code_int"} for Haskell Quickcheck's Int type *}
-
-typedef code_int = "UNIV \<Colon> int set"
-  morphisms int_of of_int by rule
-
-lemma of_int_int_of [simp]:
-  "of_int (int_of k) = k"
-  by (rule int_of_inverse)
-
-lemma int_of_of_int [simp]:
-  "int_of (of_int n) = n"
-  by (rule of_int_inverse) (rule UNIV_I)
-
-lemma code_int:
-  "(\<And>n\<Colon>code_int. PROP P n) \<equiv> (\<And>n\<Colon>int. PROP P (of_int n))"
-proof
-  fix n :: int
-  assume "\<And>n\<Colon>code_int. PROP P n"
-  then show "PROP P (of_int n)" .
-next
-  fix n :: code_int
-  assume "\<And>n\<Colon>int. PROP P (of_int n)"
-  then have "PROP P (of_int (int_of n))" .
-  then show "PROP P n" by simp
-qed
-
-
-lemma int_of_inject [simp]:
-  "int_of k = int_of l \<longleftrightarrow> k = l"
-  by (rule int_of_inject)
-
-lemma of_int_inject [simp]:
-  "of_int n = of_int m \<longleftrightarrow> n = m"
-  by (rule of_int_inject) (rule UNIV_I)+
-
-instantiation code_int :: equal
-begin
-
-definition
-  "HOL.equal k l \<longleftrightarrow> HOL.equal (int_of k) (int_of l)"
-
-instance proof
-qed (auto simp add: equal_code_int_def equal_int_def equal_int_refl)
-
-end
-
-definition nat_of :: "code_int => nat"
-where
-  "nat_of i = nat (int_of i)"
-  
-instantiation code_int :: "{minus, linordered_semidom, semiring_div, neg_numeral, linorder}"
-begin
-
-definition [simp, code del]:
-  "0 = of_int 0"
-
-definition [simp, code del]:
-  "1 = of_int 1"
-
-definition [simp, code del]:
-  "n + m = of_int (int_of n + int_of m)"
-
-definition [simp, code del]:
-  "- n = of_int (- int_of n)"
-
-definition [simp, code del]:
-  "n - m = of_int (int_of n - int_of m)"
-
-definition [simp, code del]:
-  "n * m = of_int (int_of n * int_of m)"
-
-definition [simp, code del]:
-  "n div m = of_int (int_of n div int_of m)"
-
-definition [simp, code del]:
-  "n mod m = of_int (int_of n mod int_of m)"
-
-definition [simp, code del]:
-  "n \<le> m \<longleftrightarrow> int_of n \<le> int_of m"
-
-definition [simp, code del]:
-  "n < m \<longleftrightarrow> int_of n < int_of m"
-
-instance proof
-qed (auto simp add: code_int distrib_right zmult_zless_mono2)
-
-end
-
-lemma int_of_numeral [simp]:
-  "int_of (numeral k) = numeral k"
-  by (induct k) (simp_all only: numeral.simps plus_code_int_def
-    one_code_int_def of_int_inverse UNIV_I)
-
-definition Num :: "num \<Rightarrow> code_int"
-  where [code_abbrev]: "Num = numeral"
-
-lemma [code_abbrev]:
-  "- numeral k = (neg_numeral k :: code_int)"
-  by (unfold neg_numeral_def) simp
-
-code_datatype "0::code_int" Num
-
-lemma one_code_int_code [code, code_unfold]:
-  "(1\<Colon>code_int) = Numeral1"
-  by (simp only: numeral.simps)
-
-definition div_mod :: "code_int \<Rightarrow> code_int \<Rightarrow> code_int \<times> code_int" where
-  [code del]: "div_mod n m = (n div m, n mod m)"
-
-lemma [code]:
-  "n div m = fst (div_mod n m)"
-  unfolding div_mod_def by simp
-
-lemma [code]:
-  "n mod m = snd (div_mod n m)"
-  unfolding div_mod_def by simp
-
-lemma int_of_code [code]:
-  "int_of k = (if k = 0 then 0
-    else (if k mod 2 = 0 then 2 * int_of (k div 2) else 2 * int_of (k div 2) + 1))"
-proof -
-  have 1: "(int_of k div 2) * 2 + int_of k mod 2 = int_of k" 
-    by (rule mod_div_equality)
-  have "int_of k mod 2 = 0 \<or> int_of k mod 2 = 1" by auto
-  from this show ?thesis
-    apply auto
-    apply (insert 1) by (auto simp add: mult_ac)
-qed
-
-
-code_instance code_numeral :: equal
-  (Haskell_Quickcheck -)
-
-setup {* fold (Numeral.add_code @{const_name Num}
-  false Code_Printer.literal_numeral) ["Haskell_Quickcheck"]  *}
-
-code_type code_int
-  (Haskell_Quickcheck "Prelude.Int")
-
-code_const "0 \<Colon> code_int"
-  (Haskell_Quickcheck "0")
-
-code_const "1 \<Colon> code_int"
-  (Haskell_Quickcheck "1")
-
-code_const "minus \<Colon> code_int \<Rightarrow> code_int \<Rightarrow> code_int"
-  (Haskell_Quickcheck infixl 6 "-")
-
-code_const div_mod
-  (Haskell_Quickcheck "divMod")
-
-code_const "HOL.equal \<Colon> code_int \<Rightarrow> code_int \<Rightarrow> bool"
-  (Haskell_Quickcheck infix 4 "==")
-
-code_const "less_eq \<Colon> code_int \<Rightarrow> code_int \<Rightarrow> bool"
-  (Haskell_Quickcheck infix 4 "<=")
-
-code_const "less \<Colon> code_int \<Rightarrow> code_int \<Rightarrow> bool"
-  (Haskell_Quickcheck infix 4 "<")
-
-code_abort of_int
-
-hide_const (open) Num div_mod
 
 subsubsection {* Narrowing's deep representation of types and terms *}
 
 datatype narrowing_type = Narrowing_sum_of_products "narrowing_type list list"
-datatype narrowing_term = Narrowing_variable "code_int list" narrowing_type | Narrowing_constructor code_int "narrowing_term list"
+datatype narrowing_term = Narrowing_variable "integer list" narrowing_type | Narrowing_constructor integer "narrowing_term list"
 datatype 'a narrowing_cons = Narrowing_cons narrowing_type "(narrowing_term list => 'a) list"
 
 primrec map_cons :: "('a => 'b) => 'a narrowing_cons => 'b narrowing_cons"
@@ -207,7 +45,7 @@
  
 subsubsection {* Auxilary functions for Narrowing *}
 
-consts nth :: "'a list => code_int => 'a"
+consts nth :: "'a list => integer => 'a"
 
 code_const nth (Haskell_Quickcheck infixl 9  "!!")
 
@@ -215,7 +53,7 @@
 
 code_const error (Haskell_Quickcheck "error")
 
-consts toEnum :: "code_int => char"
+consts toEnum :: "integer => char"
 
 code_const toEnum (Haskell_Quickcheck "Prelude.toEnum")
 
@@ -225,7 +63,7 @@
 
 subsubsection {* Narrowing's basic operations *}
 
-type_synonym 'a narrowing = "code_int => 'a narrowing_cons"
+type_synonym 'a narrowing = "integer => 'a narrowing_cons"
 
 definition empty :: "'a narrowing"
 where
@@ -267,35 +105,33 @@
 using assms unfolding sum_def by (auto split: narrowing_cons.split narrowing_type.split)
 
 lemma [fundef_cong]:
-  assumes "f d = f' d" "(\<And>d'. 0 <= d' & d' < d ==> a d' = a' d')"
+  assumes "f d = f' d" "(\<And>d'. 0 \<le> d' \<and> d' < d \<Longrightarrow> a d' = a' d')"
   assumes "d = d'"
   shows "apply f a d = apply f' a' d'"
 proof -
-  note assms moreover
-  have "int_of (of_int 0) < int_of d' ==> int_of (of_int 0) <= int_of (of_int (int_of d' - int_of (of_int 1)))"
-    by (simp add: of_int_inverse)
-  moreover
-  have "int_of (of_int (int_of d' - int_of (of_int 1))) < int_of d'"
-    by (simp add: of_int_inverse)
+  note assms
+  moreover have "0 < d' \<Longrightarrow> 0 \<le> d' - 1"
+    by (simp add: less_integer_def less_eq_integer_def)
   ultimately show ?thesis
-    unfolding apply_def by (auto split: narrowing_cons.split narrowing_type.split simp add: Let_def)
+    by (auto simp add: apply_def Let_def
+      split: narrowing_cons.split narrowing_type.split)
 qed
 
 subsubsection {* Narrowing generator type class *}
 
 class narrowing =
-  fixes narrowing :: "code_int => 'a narrowing_cons"
+  fixes narrowing :: "integer => 'a narrowing_cons"
 
 datatype property = Universal narrowing_type "(narrowing_term => property)" "narrowing_term => Code_Evaluation.term" | Existential narrowing_type "(narrowing_term => property)" "narrowing_term => Code_Evaluation.term" | Property bool
 
 (* FIXME: hard-wired maximal depth of 100 here *)
 definition exists :: "('a :: {narrowing, partial_term_of} => property) => property"
 where
-  "exists f = (case narrowing (100 :: code_int) of Narrowing_cons ty cs => Existential ty (\<lambda> t. f (conv cs t)) (partial_term_of (TYPE('a))))"
+  "exists f = (case narrowing (100 :: integer) of Narrowing_cons ty cs => Existential ty (\<lambda> t. f (conv cs t)) (partial_term_of (TYPE('a))))"
 
 definition "all" :: "('a :: {narrowing, partial_term_of} => property) => property"
 where
-  "all f = (case narrowing (100 :: code_int) of Narrowing_cons ty cs => Universal ty (\<lambda>t. f (conv cs t)) (partial_term_of (TYPE('a))))"
+  "all f = (case narrowing (100 :: integer) of Narrowing_cons ty cs => Universal ty (\<lambda>t. f (conv cs t)) (partial_term_of (TYPE('a))))"
 
 subsubsection {* class @{text is_testable} *}
 
@@ -343,14 +179,14 @@
 where
   "narrowing_dummy_partial_term_of = partial_term_of"
 
-definition narrowing_dummy_narrowing :: "code_int => ('a :: narrowing) narrowing_cons"
+definition narrowing_dummy_narrowing :: "integer => ('a :: narrowing) narrowing_cons"
 where
   "narrowing_dummy_narrowing = narrowing"
 
 lemma [code]:
   "ensure_testable f =
     (let
-      x = narrowing_dummy_narrowing :: code_int => bool narrowing_cons;
+      x = narrowing_dummy_narrowing :: integer => bool narrowing_cons;
       y = narrowing_dummy_partial_term_of :: bool itself => narrowing_term => term;
       z = (conv :: _ => _ => unit)  in f)"
 unfolding Let_def ensure_testable_def ..
@@ -369,47 +205,76 @@
 subsection {* Narrowing for integers *}
 
 
-definition drawn_from :: "'a list => 'a narrowing_cons"
-where "drawn_from xs = Narrowing_cons (Narrowing_sum_of_products (map (%_. []) xs)) (map (%x y. x) xs)"
+definition drawn_from :: "'a list \<Rightarrow> 'a narrowing_cons"
+where
+  "drawn_from xs =
+    Narrowing_cons (Narrowing_sum_of_products (map (\<lambda>_. []) xs)) (map (\<lambda>x _. x) xs)"
 
-function around_zero :: "int => int list"
+function around_zero :: "int \<Rightarrow> int list"
 where
   "around_zero i = (if i < 0 then [] else (if i = 0 then [0] else around_zero (i - 1) @ [i, -i]))"
-by pat_completeness auto
+  by pat_completeness auto
 termination by (relation "measure nat") auto
 
-declare around_zero.simps[simp del]
+declare around_zero.simps [simp del]
 
 lemma length_around_zero:
   assumes "i >= 0" 
   shows "length (around_zero i) = 2 * nat i + 1"
-proof (induct rule: int_ge_induct[OF assms])
+proof (induct rule: int_ge_induct [OF assms])
   case 1
   from 1 show ?case by (simp add: around_zero.simps)
 next
   case (2 i)
   from 2 show ?case
-    by (simp add: around_zero.simps[of "i + 1"])
+    by (simp add: around_zero.simps [of "i + 1"])
 qed
 
 instantiation int :: narrowing
 begin
 
 definition
-  "narrowing_int d = (let (u :: _ => _ => unit) = conv; i = Quickcheck_Narrowing.int_of d in drawn_from (around_zero i))"
+  "narrowing_int d = (let (u :: _ \<Rightarrow> _ \<Rightarrow> unit) = conv; i = int_of_integer d
+    in drawn_from (around_zero i))"
 
 instance ..
 
 end
 
-lemma [code, code del]: "partial_term_of (ty :: int itself) t == undefined"
-by (rule partial_term_of_anything)+
+lemma [code, code del]: "partial_term_of (ty :: int itself) t \<equiv> undefined"
+  by (rule partial_term_of_anything)+
 
 lemma [code]:
-  "partial_term_of (ty :: int itself) (Narrowing_variable p t) == Code_Evaluation.Free (STR ''_'') (Typerep.Typerep (STR ''Int.int'') [])"
-  "partial_term_of (ty :: int itself) (Narrowing_constructor i []) == (if i mod 2 = 0 then
-     Code_Evaluation.term_of (- (int_of i) div 2) else Code_Evaluation.term_of ((int_of i + 1) div 2))"
-by (rule partial_term_of_anything)+
+  "partial_term_of (ty :: int itself) (Narrowing_variable p t) \<equiv>
+    Code_Evaluation.Free (STR ''_'') (Typerep.Typerep (STR ''Int.int'') [])"
+  "partial_term_of (ty :: int itself) (Narrowing_constructor i []) \<equiv>
+    (if i mod 2 = 0
+     then Code_Evaluation.term_of (- (int_of_integer i) div 2)
+     else Code_Evaluation.term_of ((int_of_integer i + 1) div 2))"
+  by (rule partial_term_of_anything)+
+
+instantiation integer :: narrowing
+begin
+
+definition
+  "narrowing_integer d = (let (u :: _ \<Rightarrow> _ \<Rightarrow> unit) = conv; i = int_of_integer d
+    in drawn_from (map integer_of_int (around_zero i)))"
+
+instance ..
+
+end
+
+lemma [code, code del]: "partial_term_of (ty :: integer itself) t \<equiv> undefined"
+  by (rule partial_term_of_anything)+
+
+lemma [code]:
+  "partial_term_of (ty :: integer itself) (Narrowing_variable p t) \<equiv>
+    Code_Evaluation.Free (STR ''_'') (Typerep.Typerep (STR ''Code_Numeral.integer'') [])"
+  "partial_term_of (ty :: integer itself) (Narrowing_constructor i []) \<equiv>
+    (if i mod 2 = 0
+     then Code_Evaluation.term_of (- i div 2)
+     else Code_Evaluation.term_of ((i + 1) div 2))"
+  by (rule partial_term_of_anything)+
 
 
 subsection {* The @{text find_unused_assms} command *}
@@ -418,9 +283,10 @@
 
 subsection {* Closing up *}
 
-hide_type code_int narrowing_type narrowing_term narrowing_cons property
-hide_const int_of of_int nat_of map_cons nth error toEnum marker empty Narrowing_cons conv non_empty ensure_testable all exists drawn_from around_zero
+hide_type narrowing_type narrowing_term narrowing_cons property
+hide_const map_cons nth error toEnum marker empty Narrowing_cons conv non_empty ensure_testable all exists drawn_from around_zero
 hide_const (open) Narrowing_variable Narrowing_constructor "apply" sum cons
 hide_fact empty_def cons_def conv.simps non_empty.simps apply_def sum_def ensure_testable_def all_def exists_def
 
 end
+