src/HOL/Analysis/Abstract_Topology.thy
changeset 73932 fd21b4a93043
parent 72608 ad45ae49be85
child 75449 51e05af57455
equal deleted inserted replaced
73866:66bff50bc5f1 73932:fd21b4a93043
  2115   shows "continuous_map X' X'' g"
  2115   shows "continuous_map X' X'' g"
  2116   unfolding quotient_map_def continuous_map_def
  2116   unfolding quotient_map_def continuous_map_def
  2117 proof (intro conjI ballI allI impI)
  2117 proof (intro conjI ballI allI impI)
  2118   show "\<And>x'. x' \<in> topspace X' \<Longrightarrow> g x' \<in> topspace X''"
  2118   show "\<And>x'. x' \<in> topspace X' \<Longrightarrow> g x' \<in> topspace X''"
  2119     using assms unfolding quotient_map_def
  2119     using assms unfolding quotient_map_def
  2120     by (metis (no_types, hide_lams) continuous_map_image_subset_topspace image_comp image_subset_iff)
  2120     by (metis (no_types, opaque_lifting) continuous_map_image_subset_topspace image_comp image_subset_iff)
  2121 next
  2121 next
  2122   fix U'' :: "'c set"
  2122   fix U'' :: "'c set"
  2123   assume U'': "openin X'' U''"
  2123   assume U'': "openin X'' U''"
  2124   have "f ` topspace X = topspace X'"
  2124   have "f ` topspace X = topspace X'"
  2125     by (simp add: f quotient_imp_surjective_map)
  2125     by (simp add: f quotient_imp_surjective_map)
  3800    "retraction_map X Y f \<Longrightarrow> f ` (topspace X) = topspace Y"
  3800    "retraction_map X Y f \<Longrightarrow> f ` (topspace X) = topspace Y"
  3801   by (simp add: retraction_imp_quotient_map quotient_imp_surjective_map)
  3801   by (simp add: retraction_imp_quotient_map quotient_imp_surjective_map)
  3802 
  3802 
  3803 lemma section_imp_injective_map:
  3803 lemma section_imp_injective_map:
  3804    "\<lbrakk>section_map X Y f; x \<in> topspace X; y \<in> topspace X\<rbrakk> \<Longrightarrow> f x = f y \<longleftrightarrow> x = y"
  3804    "\<lbrakk>section_map X Y f; x \<in> topspace X; y \<in> topspace X\<rbrakk> \<Longrightarrow> f x = f y \<longleftrightarrow> x = y"
  3805   by (metis (mono_tags, hide_lams) retraction_maps_def section_map_def)
  3805   by (metis (mono_tags, opaque_lifting) retraction_maps_def section_map_def)
  3806 
  3806 
  3807 lemma retraction_maps_to_retract_maps:
  3807 lemma retraction_maps_to_retract_maps:
  3808    "retraction_maps X Y r s
  3808    "retraction_maps X Y r s
  3809         \<Longrightarrow> retraction_maps X (subtopology X (s ` (topspace Y))) (s \<circ> r) id"
  3809         \<Longrightarrow> retraction_maps X (subtopology X (s ` (topspace Y))) (s \<circ> r) id"
  3810   unfolding retraction_maps_def
  3810   unfolding retraction_maps_def