src/HOL/Library/FrechetDeriv.thy
changeset 30729 461ee3e49ad3
parent 30663 0b6aff7451b2
child 31021 53642251a04f
equal deleted inserted replaced
30728:f0aeca99b5d9 30729:461ee3e49ad3
   220   let ?Rf = "\<lambda>h. f (x + h) - f x - F h"
   220   let ?Rf = "\<lambda>h. f (x + h) - f x - F h"
   221   let ?Rg = "\<lambda>k. g (f x + k) - g (f x) - G k"
   221   let ?Rg = "\<lambda>k. g (f x + k) - g (f x) - G k"
   222   let ?k = "\<lambda>h. f (x + h) - f x"
   222   let ?k = "\<lambda>h. f (x + h) - f x"
   223   let ?Nf = "\<lambda>h. norm (?Rf h) / norm h"
   223   let ?Nf = "\<lambda>h. norm (?Rf h) / norm h"
   224   let ?Ng = "\<lambda>h. norm (?Rg (?k h)) / norm (?k h)"
   224   let ?Ng = "\<lambda>h. norm (?Rg (?k h)) / norm (?k h)"
   225   from f interpret F!: bounded_linear "F" by (rule FDERIV_bounded_linear)
   225   from f interpret F: bounded_linear "F" by (rule FDERIV_bounded_linear)
   226   from g interpret G!: bounded_linear "G" by (rule FDERIV_bounded_linear)
   226   from g interpret G: bounded_linear "G" by (rule FDERIV_bounded_linear)
   227   from F.bounded obtain kF where kF: "\<And>x. norm (F x) \<le> norm x * kF" by fast
   227   from F.bounded obtain kF where kF: "\<And>x. norm (F x) \<le> norm x * kF" by fast
   228   from G.bounded obtain kG where kG: "\<And>x. norm (G x) \<le> norm x * kG" by fast
   228   from G.bounded obtain kG where kG: "\<And>x. norm (G x) \<le> norm x * kG" by fast
   229 
   229 
   230   let ?fun2 = "\<lambda>h. ?Nf h * kG + ?Ng h * (?Nf h + kF)"
   230   let ?fun2 = "\<lambda>h. ?Nf h * kG + ?Ng h * (?Nf h + kF)"
   231 
   231