777 |
777 |
778 lemma tendsto_mult_right: "(f \<longlongrightarrow> l) F \<Longrightarrow> ((\<lambda>x. (f x) * c) \<longlongrightarrow> l * c) F" |
778 lemma tendsto_mult_right: "(f \<longlongrightarrow> l) F \<Longrightarrow> ((\<lambda>x. (f x) * c) \<longlongrightarrow> l * c) F" |
779 for c :: "'a::topological_semigroup_mult" |
779 for c :: "'a::topological_semigroup_mult" |
780 by (rule tendsto_mult [OF _ tendsto_const]) |
780 by (rule tendsto_mult [OF _ tendsto_const]) |
781 |
781 |
782 lemma real_tendsto_mult_left_iff: |
782 lemma tendsto_mult_left_iff: |
783 "c \<noteq> 0 \<Longrightarrow> tendsto(\<lambda>x. c * f x) (c * l) F \<longleftrightarrow> tendsto f l F" for c :: real |
783 "c \<noteq> 0 \<Longrightarrow> tendsto(\<lambda>x. c * f x) (c * l) F \<longleftrightarrow> tendsto f l F" for c :: "'a::{topological_semigroup_mult,field}" |
784 by (auto simp: tendsto_mult_left dest: tendsto_mult_left [where c = "1/c"]) |
784 by (auto simp: tendsto_mult_left dest: tendsto_mult_left [where c = "1/c"]) |
785 |
785 |
786 lemma real_tendsto_mult_right_iff: |
786 lemma tendsto_mult_right_iff: |
787 "c \<noteq> 0 \<Longrightarrow> tendsto(\<lambda>x. f x * c) (l * c) F \<longleftrightarrow> tendsto f l F" for c :: real |
787 "c \<noteq> 0 \<Longrightarrow> tendsto(\<lambda>x. f x * c) (l * c) F \<longleftrightarrow> tendsto f l F" for c :: "'a::{topological_semigroup_mult,field}" |
788 by (simp add: mult.commute real_tendsto_mult_left_iff) |
788 by (auto simp: tendsto_mult_right dest: tendsto_mult_left [where c = "1/c"]) |
789 |
789 |
790 lemma lim_const_over_n [tendsto_intros]: |
790 lemma lim_const_over_n [tendsto_intros]: |
791 fixes a :: "'a::real_normed_field" |
791 fixes a :: "'a::real_normed_field" |
792 shows "(\<lambda>n. a / of_nat n) \<longlonglongrightarrow> 0" |
792 shows "(\<lambda>n. a / of_nat n) \<longlonglongrightarrow> 0" |
793 using tendsto_mult [OF tendsto_const [of a] lim_1_over_n] by simp |
793 using tendsto_mult [OF tendsto_const [of a] lim_1_over_n] by simp |