src/HOL/Library/Abstract_Rat.thy
changeset 27556 292098f2efdf
parent 27368 9f90ac19e32b
child 27567 e3fe9a327c63
--- a/src/HOL/Library/Abstract_Rat.thy	Fri Jul 11 23:17:25 2008 +0200
+++ b/src/HOL/Library/Abstract_Rat.thy	Mon Jul 14 11:04:42 2008 +0200
@@ -22,13 +22,13 @@
 definition
   isnormNum :: "Num \<Rightarrow> bool"
 where
-  "isnormNum = (\<lambda>(a,b). (if a = 0 then b = 0 else b > 0 \<and> igcd a b = 1))"
+  "isnormNum = (\<lambda>(a,b). (if a = 0 then b = 0 else b > 0 \<and> zgcd a b = 1))"
 
 definition
   normNum :: "Num \<Rightarrow> Num"
 where
   "normNum = (\<lambda>(a,b). (if a=0 \<or> b = 0 then (0,0) else 
-  (let g = igcd a b 
+  (let g = zgcd a b 
    in if b > 0 then (a div g, b div g) else (- (a div g), - (b div g)))))"
 
 lemma normNum_isnormNum [simp]: "isnormNum (normNum x)"
@@ -38,19 +38,19 @@
   {assume "a=0 \<or> b = 0" hence ?thesis by (simp add: normNum_def isnormNum_def)}  
   moreover
   {assume anz: "a \<noteq> 0" and bnz: "b \<noteq> 0" 
-    let ?g = "igcd a b"
+    let ?g = "zgcd a b"
     let ?a' = "a div ?g"
     let ?b' = "b div ?g"
-    let ?g' = "igcd ?a' ?b'"
-    from anz bnz have "?g \<noteq> 0" by simp  with igcd_pos[of a b] 
+    let ?g' = "zgcd ?a' ?b'"
+    from anz bnz have "?g \<noteq> 0" by simp  with zgcd_pos[of a b] 
     have gpos: "?g > 0"  by arith
-    have gdvd: "?g dvd a" "?g dvd b" by (simp_all add: igcd_dvd1 igcd_dvd2)
+    have gdvd: "?g dvd a" "?g dvd b" by (simp_all add: zgcd_dvd1 zgcd_dvd2)
     from zdvd_mult_div_cancel[OF gdvd(1)] zdvd_mult_div_cancel[OF gdvd(2)]
     anz bnz
     have nz':"?a' \<noteq> 0" "?b' \<noteq> 0" 
-      by - (rule notI,simp add:igcd_def)+
+      by - (rule notI,simp add:zgcd_def)+
     from anz bnz have stupid: "a \<noteq> 0 \<or> b \<noteq> 0" by blast
-    from div_igcd_relprime[OF stupid] have gp1: "?g' = 1" .
+    from div_zgcd_relprime[OF stupid] have gp1: "?g' = 1" .
     from bnz have "b < 0 \<or> b > 0" by arith
     moreover
     {assume b: "b > 0"
@@ -84,7 +84,7 @@
 definition
   Nmul :: "Num \<Rightarrow> Num \<Rightarrow> Num" (infixl "*\<^sub>N" 60)
 where
-  "Nmul = (\<lambda>(a,b) (a',b'). let g = igcd (a*a') (b*b') 
+  "Nmul = (\<lambda>(a,b) (a',b'). let g = zgcd (a*a') (b*b') 
     in (a*a' div g, b*b' div g))"
 
 definition
@@ -120,11 +120,11 @@
   then obtain a b a' b' where ab: "x = (a,b)"  and ab': "y = (a',b')" by blast 
   {assume "a = 0"
     hence ?thesis using xn ab ab'
-      by (simp add: igcd_def isnormNum_def Let_def Nmul_def split_def)}
+      by (simp add: zgcd_def isnormNum_def Let_def Nmul_def split_def)}
   moreover
   {assume "a' = 0"
     hence ?thesis using yn ab ab' 
-      by (simp add: igcd_def isnormNum_def Let_def Nmul_def split_def)}
+      by (simp add: zgcd_def isnormNum_def Let_def Nmul_def split_def)}
   moreover
   {assume a: "a \<noteq>0" and a': "a'\<noteq>0"
     hence bp: "b > 0" "b' > 0" using xn yn ab ab' by (simp_all add: isnormNum_def)
@@ -136,11 +136,11 @@
 
 lemma Ninv_normN[simp]: "isnormNum x \<Longrightarrow> isnormNum (Ninv x)"
   by (simp add: Ninv_def isnormNum_def split_def)
-    (cases "fst x = 0", auto simp add: igcd_commute)
+    (cases "fst x = 0", auto simp add: zgcd_commute)
 
 lemma isnormNum_int[simp]: 
   "isnormNum 0\<^sub>N" "isnormNum (1::int)\<^sub>N" "i \<noteq> 0 \<Longrightarrow> isnormNum i\<^sub>N"
-  by (simp_all add: isnormNum_def igcd_def)
+  by (simp_all add: isnormNum_def zgcd_def)
 
 
 text {* Relations over Num *}
@@ -201,8 +201,8 @@
     from az bz a'z b'z na nb have pos: "b > 0" "b' > 0" by (simp_all add: isnormNum_def)
     from prems have eq:"a * b' = a'*b" 
       by (simp add: INum_def  eq_divide_eq divide_eq_eq of_int_mult[symmetric] del: of_int_mult)
-    from prems have gcd1: "igcd a b = 1" "igcd b a = 1" "igcd a' b' = 1" "igcd b' a' = 1"       
-      by (simp_all add: isnormNum_def add: igcd_commute)
+    from prems have gcd1: "zgcd a b = 1" "zgcd b a = 1" "zgcd a' b' = 1" "zgcd b' a' = 1"       
+      by (simp_all add: isnormNum_def add: zgcd_commute)
     from eq have raw_dvd: "a dvd a'*b" "b dvd b'*a" "a' dvd a*b'" "b' dvd b*a'" 
       apply(unfold dvd_def)
       apply (rule_tac x="b'" in exI, simp add: mult_ac)
@@ -257,7 +257,7 @@
       by (simp add: INum_def normNum_def split_def Let_def)}
   moreover 
   {assume a: "a\<noteq>0" and b: "b\<noteq>0"
-    let ?g = "igcd a b"
+    let ?g = "zgcd a b"
     from a b have g: "?g \<noteq> 0"by simp
     from of_int_div[OF g, where ?'a = 'a]
     have ?thesis by (auto simp add: INum_def normNum_def split_def Let_def)}
@@ -293,13 +293,13 @@
       from z aa' bb' have ?thesis 
 	by (simp add: th Nadd_def normNum_def INum_def split_def)}
     moreover {assume z: "a * b' + b * a' \<noteq> 0"
-      let ?g = "igcd (a * b' + b * a') (b*b')"
+      let ?g = "zgcd (a * b' + b * a') (b*b')"
       have gz: "?g \<noteq> 0" using z by simp
       have ?thesis using aa' bb' z gz
 	of_int_div[where ?'a = 'a, 
-	OF gz igcd_dvd1[where i="a * b' + b * a'" and j="b*b'"]]
+	OF gz zgcd_dvd1[where i="a * b' + b * a'" and j="b*b'"]]
 	of_int_div[where ?'a = 'a,
-	OF gz igcd_dvd2[where i="a * b' + b * a'" and j="b*b'"]]
+	OF gz zgcd_dvd2[where i="a * b' + b * a'" and j="b*b'"]]
 	by (simp add: x y Nadd_def INum_def normNum_def Let_def add_divide_distrib)}
     ultimately have ?thesis using aa' bb' 
       by (simp add: Nadd_def INum_def normNum_def x y Let_def) }
@@ -318,10 +318,10 @@
       done }
   moreover
   {assume z: "a \<noteq> 0" "a' \<noteq> 0" "b \<noteq> 0" "b' \<noteq> 0"
-    let ?g="igcd (a*a') (b*b')"
+    let ?g="zgcd (a*a') (b*b')"
     have gz: "?g \<noteq> 0" using z by simp
-    from z of_int_div[where ?'a = 'a, OF gz igcd_dvd1[where i="a*a'" and j="b*b'"]] 
-      of_int_div[where ?'a = 'a , OF gz igcd_dvd2[where i="a*a'" and j="b*b'"]] 
+    from z of_int_div[where ?'a = 'a, OF gz zgcd_dvd1[where i="a*a'" and j="b*b'"]] 
+      of_int_div[where ?'a = 'a , OF gz zgcd_dvd2[where i="a*a'" and j="b*b'"]] 
     have ?thesis by (simp add: Nmul_def x y Let_def INum_def)}
   ultimately show ?thesis by blast
 qed
@@ -456,7 +456,7 @@
 qed
 
 lemma Nmul_commute: "isnormNum x \<Longrightarrow> isnormNum y \<Longrightarrow> x *\<^sub>N y = y *\<^sub>N x"
-  by (simp add: Nmul_def split_def Let_def igcd_commute mult_commute)
+  by (simp add: Nmul_def split_def Let_def zgcd_commute mult_commute)
 
 lemma Nmul_assoc: assumes nx: "isnormNum x" and ny:"isnormNum y" and nz:"isnormNum z"
   shows "x *\<^sub>N y *\<^sub>N z = x *\<^sub>N (y *\<^sub>N z)"