src/HOL/Real/RealVector.thy
changeset 20684 74e8b46abb97
parent 20584 60b1d52a455d
child 20694 76c49548d14c
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20683:3d07617c8bf3 20684:74e8b46abb97
     4 *)
     4 *)
     5 
     5 
     6 header {* Vector Spaces and Algebras over the Reals *}
     6 header {* Vector Spaces and Algebras over the Reals *}
     7 
     7 
     8 theory RealVector
     8 theory RealVector
     9 imports RealDef
     9 imports RealPow
    10 begin
    10 begin
    11 
    11 
    12 subsection {* Locale for additive functions *}
    12 subsection {* Locale for additive functions *}
    13 
    13 
    14 locale additive =
    14 locale additive =
   487 lemma norm_divide:
   487 lemma norm_divide:
   488   fixes a b :: "'a::{real_normed_field,division_by_zero}"
   488   fixes a b :: "'a::{real_normed_field,division_by_zero}"
   489   shows "norm (a / b) = norm a / norm b"
   489   shows "norm (a / b) = norm a / norm b"
   490 by (simp add: divide_inverse norm_mult norm_inverse)
   490 by (simp add: divide_inverse norm_mult norm_inverse)
   491 
   491 
       
   492 lemma norm_power:
       
   493   fixes x :: "'a::{real_normed_div_algebra,recpower}"
       
   494   shows "norm (x ^ n) = norm x ^ n"
       
   495 by (induct n, simp, simp add: power_Suc norm_mult)
       
   496 
   492 end
   497 end