src/HOL/Library/Convex_Euclidean_Space.thy
changeset 31407 689df1591793
parent 31401 2da6a7684e66
parent 31362 edf74583715a
child 31418 9baa48bad81c
equal deleted inserted replaced
31406:e23dd3aac0fb 31407:689df1591793
     1 (* Title:      Convex
     1 (*  Title:      HOL/Library/Convex_Euclidean_Space.thy
     2    ID:         $Id: 
     2     Author:     Robert Himmelmann, TU Muenchen
     3    Author:     Robert Himmelmann, TU Muenchen*)
     3 *)
     4 
     4 
     5 header {* Convex sets, functions and related things. *}
     5 header {* Convex sets, functions and related things. *}
     6 
     6 
     7 theory Convex_Euclidean_Space
     7 theory Convex_Euclidean_Space
     8   imports Topology_Euclidean_Space
     8   imports Topology_Euclidean_Space
  2194   using is_interval_convex convex_connected by auto
  2194   using is_interval_convex convex_connected by auto
  2195 
  2195 
  2196 lemma convex_interval: "convex {a .. b}" "convex {a<..<b::real^'n::finite}"
  2196 lemma convex_interval: "convex {a .. b}" "convex {a<..<b::real^'n::finite}"
  2197   apply(rule_tac[!] is_interval_convex) using is_interval_interval by auto
  2197   apply(rule_tac[!] is_interval_convex) using is_interval_interval by auto
  2198 
  2198 
  2199 subsection {* On real^1, is_interval, convex and connected are all equivalent. *}
  2199 subsection {* On @{text "real^1"}, @{text "is_interval"}, @{text "convex"} and @{text "connected"} are all equivalent. *}
  2200 
  2200 
  2201 lemma is_interval_1:
  2201 lemma is_interval_1:
  2202   "is_interval s \<longleftrightarrow> (\<forall>a\<in>s. \<forall>b\<in>s. \<forall> x. dest_vec1 a \<le> dest_vec1 x \<and> dest_vec1 x \<le> dest_vec1 b \<longrightarrow> x \<in> s)"
  2202   "is_interval s \<longleftrightarrow> (\<forall>a\<in>s. \<forall>b\<in>s. \<forall> x. dest_vec1 a \<le> dest_vec1 x \<and> dest_vec1 x \<le> dest_vec1 b \<longrightarrow> x \<in> s)"
  2203   unfolding is_interval_def dest_vec1_def forall_1 by auto
  2203   unfolding is_interval_def dest_vec1_def forall_1 by auto
  2204 
  2204