src/HOL/Analysis/Henstock_Kurzweil_Integration.thy
changeset 66296 33a47f2d9edc
parent 66294 0442b3f45556
child 66299 1b4aa3e3e4e6
equal deleted inserted replaced
66295:1ec601d9c829 66296:33a47f2d9edc
    43 lemma content_cbox: "\<forall>i\<in>Basis. a\<bullet>i \<le> b\<bullet>i \<Longrightarrow> content (cbox a b) = (\<Prod>i\<in>Basis. b\<bullet>i - a\<bullet>i)"
    43 lemma content_cbox: "\<forall>i\<in>Basis. a\<bullet>i \<le> b\<bullet>i \<Longrightarrow> content (cbox a b) = (\<Prod>i\<in>Basis. b\<bullet>i - a\<bullet>i)"
    44   unfolding content_cbox_cases by simp
    44   unfolding content_cbox_cases by simp
    45 
    45 
    46 lemma content_cbox': "cbox a b \<noteq> {} \<Longrightarrow> content (cbox a b) = (\<Prod>i\<in>Basis. b\<bullet>i - a\<bullet>i)"
    46 lemma content_cbox': "cbox a b \<noteq> {} \<Longrightarrow> content (cbox a b) = (\<Prod>i\<in>Basis. b\<bullet>i - a\<bullet>i)"
    47   by (simp add: box_ne_empty inner_diff)
    47   by (simp add: box_ne_empty inner_diff)
       
    48 
       
    49 lemma content_cbox_if: "content (cbox a b) = (if cbox a b = {} then 0 else \<Prod>i\<in>Basis. b\<bullet>i - a\<bullet>i)"
       
    50   by (simp add: content_cbox')
       
    51 
       
    52 lemma content_division_of:
       
    53   assumes "K \<in> \<D>" "\<D> division_of S"
       
    54   shows "content K = (\<Prod>i \<in> Basis. interval_upperbound K \<bullet> i - interval_lowerbound K \<bullet> i)"
       
    55 proof -
       
    56   obtain a b where "K = cbox a b"
       
    57     using cbox_division_memE assms by metis
       
    58   then show ?thesis
       
    59     using assms by (force simp: division_of_def content_cbox')
       
    60 qed
    48 
    61 
    49 lemma content_real: "a \<le> b \<Longrightarrow> content {a..b} = b - a"
    62 lemma content_real: "a \<le> b \<Longrightarrow> content {a..b} = b - a"
    50   by simp
    63   by simp
    51 
    64 
    52 lemma abs_eq_content: "\<bar>y - x\<bar> = (if x\<le>y then content {x .. y} else content {y..x})"
    65 lemma abs_eq_content: "\<bar>y - x\<bar> = (if x\<le>y then content {x .. y} else content {y..x})"