1224 obtain a where "a \<noteq> 0" and a: "span S \<subseteq> {x. a \<bullet> x = 0}" |
1224 obtain a where "a \<noteq> 0" and a: "span S \<subseteq> {x. a \<bullet> x = 0}" |
1225 using lowdim_subset_hyperplane [OF assms] by blast |
1225 using lowdim_subset_hyperplane [OF assms] by blast |
1226 have "negligible (span S)" |
1226 have "negligible (span S)" |
1227 using \<open>a \<noteq> 0\<close> a negligible_hyperplane by (blast intro: negligible_subset) |
1227 using \<open>a \<noteq> 0\<close> a negligible_hyperplane by (blast intro: negligible_subset) |
1228 then show ?thesis |
1228 then show ?thesis |
1229 using span_inc by (blast intro: negligible_subset) |
1229 using span_base by (blast intro: negligible_subset) |
1230 qed |
1230 qed |
1231 |
1231 |
1232 proposition negligible_convex_frontier: |
1232 proposition negligible_convex_frontier: |
1233 fixes S :: "'N :: euclidean_space set" |
1233 fixes S :: "'N :: euclidean_space set" |
1234 assumes "convex S" |
1234 assumes "convex S" |
1238 proof - |
1238 proof - |
1239 obtain B where "B \<subseteq> S" and indB: "independent B" |
1239 obtain B where "B \<subseteq> S" and indB: "independent B" |
1240 and spanB: "S \<subseteq> span B" and cardB: "card B = dim S" |
1240 and spanB: "S \<subseteq> span B" and cardB: "card B = dim S" |
1241 by (metis basis_exists) |
1241 by (metis basis_exists) |
1242 consider "dim S < DIM('N)" | "dim S = DIM('N)" |
1242 consider "dim S < DIM('N)" | "dim S = DIM('N)" |
1243 using dim_subset_UNIV le_eq_less_or_eq by blast |
1243 using dim_subset_UNIV le_eq_less_or_eq by auto |
1244 then show ?thesis |
1244 then show ?thesis |
1245 proof cases |
1245 proof cases |
1246 case 1 |
1246 case 1 |
1247 show ?thesis |
1247 show ?thesis |
1248 by (rule negligible_subset [of "closure S"]) |
1248 by (rule negligible_subset [of "closure S"]) |
2846 have "negligible (frontier(g ` K \<inter> g ` L) \<union> interior(g ` K \<inter> g ` L))" |
2846 have "negligible (frontier(g ` K \<inter> g ` L) \<union> interior(g ` K \<inter> g ` L))" |
2847 proof (rule negligible_Un) |
2847 proof (rule negligible_Un) |
2848 show "negligible (frontier (g ` K \<inter> g ` L))" |
2848 show "negligible (frontier (g ` K \<inter> g ` L))" |
2849 by (simp add: negligible_convex_frontier convex_Int conv convex_linear_image that) |
2849 by (simp add: negligible_convex_frontier convex_Int conv convex_linear_image that) |
2850 next |
2850 next |
2851 show "negligible (interior (g ` K \<inter> g ` L))" |
2851 have "\<forall>p N. pairwise p N = (\<forall>Na. (Na::'n set) \<in> N \<longrightarrow> (\<forall>Nb. Nb \<in> N \<and> Na \<noteq> Nb \<longrightarrow> p Na Nb))" |
2852 by (metis (mono_tags, lifting) True finite.emptyI image_Int image_empty interior_Int interior_injective_linear_image intint negligible_finite pairwiseD that) |
2852 by (metis pairwise_def) |
|
2853 then have "interior K \<inter> interior L = {}" |
|
2854 using intint that(2) that(3) that(4) by presburger |
|
2855 then show "negligible (interior (g ` K \<inter> g ` L))" |
|
2856 by (metis True empty_imp_negligible image_Int image_empty interior_Int interior_injective_linear_image that(1)) |
2853 qed |
2857 qed |
2854 moreover have "g ` K \<inter> g ` L \<subseteq> frontier (g ` K \<inter> g ` L) \<union> interior (g ` K \<inter> g ` L)" |
2858 moreover have "g ` K \<inter> g ` L \<subseteq> frontier (g ` K \<inter> g ` L) \<union> interior (g ` K \<inter> g ` L)" |
2855 apply (auto simp: frontier_def) |
2859 apply (auto simp: frontier_def) |
2856 using closure_subset contra_subsetD by fastforce+ |
2860 using closure_subset contra_subsetD by fastforce+ |
2857 ultimately show ?thesis |
2861 ultimately show ?thesis |
3174 lemma absolutely_integrable_norm: |
3178 lemma absolutely_integrable_norm: |
3175 fixes f :: "'a :: euclidean_space \<Rightarrow> 'b :: euclidean_space" |
3179 fixes f :: "'a :: euclidean_space \<Rightarrow> 'b :: euclidean_space" |
3176 assumes "f absolutely_integrable_on S" |
3180 assumes "f absolutely_integrable_on S" |
3177 shows "(norm o f) absolutely_integrable_on S" |
3181 shows "(norm o f) absolutely_integrable_on S" |
3178 using assms by (simp add: absolutely_integrable_on_def o_def) |
3182 using assms by (simp add: absolutely_integrable_on_def o_def) |
3179 |
3183 |
3180 lemma absolutely_integrable_abs: |
3184 lemma absolutely_integrable_abs: |
3181 fixes f :: "'a :: euclidean_space \<Rightarrow> 'b :: euclidean_space" |
3185 fixes f :: "'a :: euclidean_space \<Rightarrow> 'b :: euclidean_space" |
3182 assumes "f absolutely_integrable_on S" |
3186 assumes "f absolutely_integrable_on S" |
3183 shows "(\<lambda>x. \<Sum>i\<in>Basis. \<bar>f x \<bullet> i\<bar> *\<^sub>R i) absolutely_integrable_on S" |
3187 shows "(\<lambda>x. \<Sum>i\<in>Basis. \<bar>f x \<bullet> i\<bar> *\<^sub>R i) absolutely_integrable_on S" |
3184 (is "?g absolutely_integrable_on S") |
3188 (is "?g absolutely_integrable_on S") |