src/HOL/Analysis/Euclidean_Space.thy
changeset 67685 bdff8bf0a75b
parent 67399 eab6ce8368fa
child 67962 0acdcd8f4ba1
equal deleted inserted replaced
67682:00c436488398 67685:bdff8bf0a75b
    81   "b = (\<Sum>i\<in>Basis. f i *\<^sub>R i) \<longleftrightarrow> (\<forall>i\<in>Basis. f i = inner b i)"
    81   "b = (\<Sum>i\<in>Basis. f i *\<^sub>R i) \<longleftrightarrow> (\<forall>i\<in>Basis. f i = inner b i)"
    82   by (auto simp add: euclidean_representation_sum[symmetric])
    82   by (auto simp add: euclidean_representation_sum[symmetric])
    83 
    83 
    84 lemma (in euclidean_space) euclidean_representation: "(\<Sum>b\<in>Basis. inner x b *\<^sub>R b) = x"
    84 lemma (in euclidean_space) euclidean_representation: "(\<Sum>b\<in>Basis. inner x b *\<^sub>R b) = x"
    85   unfolding euclidean_representation_sum by simp
    85   unfolding euclidean_representation_sum by simp
       
    86 
       
    87 lemma (in euclidean_space) euclidean_inner: "inner x y = (\<Sum>b\<in>Basis. (inner x b) * (inner y b))"
       
    88   by (subst (1 2) euclidean_representation [symmetric])
       
    89     (simp add: inner_sum_right inner_Basis ac_simps)
    86 
    90 
    87 lemma (in euclidean_space) choice_Basis_iff:
    91 lemma (in euclidean_space) choice_Basis_iff:
    88   fixes P :: "'a \<Rightarrow> real \<Rightarrow> bool"
    92   fixes P :: "'a \<Rightarrow> real \<Rightarrow> bool"
    89   shows "(\<forall>i\<in>Basis. \<exists>x. P i x) \<longleftrightarrow> (\<exists>x. \<forall>i\<in>Basis. P i (inner x i))"
    93   shows "(\<forall>i\<in>Basis. \<exists>x. P i x) \<longleftrightarrow> (\<exists>x. \<forall>i\<in>Basis. P i (inner x i))"
    90   unfolding bchoice_iff
    94   unfolding bchoice_iff