src/HOL/Analysis/Elementary_Metric_Spaces.thy
changeset 78890 d8045bc0544e
parent 78475 a5f6d2fc1b1f
child 79772 817d33f8aa7f
equal deleted inserted replaced
78889:88eb92a52f9b 78890:d8045bc0544e
  2995 
  2995 
  2996 lemma bounded_imp_bdd_below: "bounded S \<Longrightarrow> bdd_below (S :: real set)"
  2996 lemma bounded_imp_bdd_below: "bounded S \<Longrightarrow> bdd_below (S :: real set)"
  2997   by (auto simp: bounded_def bdd_below_def dist_real_def)
  2997   by (auto simp: bounded_def bdd_below_def dist_real_def)
  2998      (metis abs_le_D1 add.commute diff_le_eq)
  2998      (metis abs_le_D1 add.commute diff_le_eq)
  2999 
  2999 
       
  3000 lemma bounded_norm_le_SUP_norm:
       
  3001   "bounded (range f) \<Longrightarrow> norm (f x) \<le> (SUP x. norm (f x))"
       
  3002   by (auto intro!: cSUP_upper bounded_imp_bdd_above simp: bounded_norm_comp)
       
  3003 
  3000 lemma bounded_has_Sup:
  3004 lemma bounded_has_Sup:
  3001   fixes S :: "real set"
  3005   fixes S :: "real set"
  3002   assumes "bounded S"
  3006   assumes "bounded S"
  3003     and "S \<noteq> {}"
  3007     and "S \<noteq> {}"
  3004   shows "\<forall>x\<in>S. x \<le> Sup S"
  3008   shows "\<forall>x\<in>S. x \<le> Sup S"