equal
deleted
inserted
replaced
1414 |
1414 |
1415 lemma Lim_within_empty: "(f ---> l) (net within {})" |
1415 lemma Lim_within_empty: "(f ---> l) (net within {})" |
1416 unfolding tendsto_def Limits.eventually_within by simp |
1416 unfolding tendsto_def Limits.eventually_within by simp |
1417 |
1417 |
1418 lemma Lim_within_subset: "(f ---> l) (net within S) \<Longrightarrow> T \<subseteq> S \<Longrightarrow> (f ---> l) (net within T)" |
1418 lemma Lim_within_subset: "(f ---> l) (net within S) \<Longrightarrow> T \<subseteq> S \<Longrightarrow> (f ---> l) (net within T)" |
1419 unfolding tendsto_def Limits.eventually_within |
1419 unfolding tendsto_def Topological_Spaces.eventually_within |
1420 by (auto elim!: eventually_elim1) |
1420 by (auto elim!: eventually_elim1) |
1421 |
1421 |
1422 lemma Lim_Un: assumes "(f ---> l) (net within S)" "(f ---> l) (net within T)" |
1422 lemma Lim_Un: assumes "(f ---> l) (net within S)" "(f ---> l) (net within T)" |
1423 shows "(f ---> l) (net within (S \<union> T))" |
1423 shows "(f ---> l) (net within (S \<union> T))" |
1424 using assms unfolding tendsto_def Limits.eventually_within |
1424 using assms unfolding tendsto_def Limits.eventually_within |
4665 using `open U` and `f x \<in> U` |
4665 using `open U` and `f x \<in> U` |
4666 unfolding tendsto_def by fast |
4666 unfolding tendsto_def by fast |
4667 hence "eventually (\<lambda>y. f y \<noteq> a) (at x within s)" |
4667 hence "eventually (\<lambda>y. f y \<noteq> a) (at x within s)" |
4668 using `a \<notin> U` by (fast elim: eventually_mono [rotated]) |
4668 using `a \<notin> U` by (fast elim: eventually_mono [rotated]) |
4669 thus ?thesis |
4669 thus ?thesis |
4670 unfolding Limits.eventually_within Limits.eventually_at |
4670 unfolding Limits.eventually_within Metric_Spaces.eventually_at |
4671 by (rule ex_forward, cut_tac `f x \<noteq> a`, auto simp: dist_commute) |
4671 by (rule ex_forward, cut_tac `f x \<noteq> a`, auto simp: dist_commute) |
4672 qed |
4672 qed |
4673 |
4673 |
4674 lemma continuous_at_avoid: |
4674 lemma continuous_at_avoid: |
4675 fixes f :: "'a::metric_space \<Rightarrow> 'b::t1_space" |
4675 fixes f :: "'a::metric_space \<Rightarrow> 'b::t1_space" |