src/HOL/Deriv.thy
changeset 61609 77b453bd616f
parent 61552 980dd46a03fb
child 61799 4cf66f21b764
--- a/src/HOL/Deriv.thy	Tue Nov 03 11:20:21 2015 +0100
+++ b/src/HOL/Deriv.thy	Tue Nov 10 14:18:41 2015 +0000
@@ -841,9 +841,7 @@
      (auto simp: has_field_derivative_def)
 
 lemma DERIV_pow: "((\<lambda>x. x ^ n) has_field_derivative real n * (x ^ (n - Suc 0))) (at x within s)"
-  apply (cut_tac DERIV_power [OF DERIV_ident])
-  apply (simp add: real_of_nat_def)
-  done
+  using DERIV_power [OF DERIV_ident] by simp
 
 lemma DERIV_chain': "(f has_field_derivative D) (at x within s) \<Longrightarrow> DERIV g (f x) :> E \<Longrightarrow> 
   ((\<lambda>x. g (f x)) has_field_derivative E * D) (at x within s)"
@@ -881,9 +879,6 @@
     shows "DERIV (\<lambda>x. g(f x)) x :> f' * g'(f x)"
   by (metis UNIV_I DERIV_chain_s [of UNIV] assms)
 
-declare
-  DERIV_power[where 'a=real, unfolded real_of_nat_def[symmetric], derivative_intros]
-
 text\<open>Alternative definition for differentiability\<close>
 
 lemma DERIV_LIM_iff: