src/HOL/Hyperreal/NthRoot.thy
changeset 23475 c869b52a9077
parent 23441 ee218296d635
child 23477 f4b83f03cac9
equal deleted inserted replaced
23474:688987d0bab4 23475:c869b52a9077
   629 
   629 
   630 (* needed for CauchysMeanTheorem.het_base from AFP *)
   630 (* needed for CauchysMeanTheorem.het_base from AFP *)
   631 lemma real_root_pos: "0 < x \<Longrightarrow> root (Suc n) (x ^ (Suc n)) = x"
   631 lemma real_root_pos: "0 < x \<Longrightarrow> root (Suc n) (x ^ (Suc n)) = x"
   632 by (rule real_root_power_cancel [OF zero_less_Suc order_less_imp_le])
   632 by (rule real_root_power_cancel [OF zero_less_Suc order_less_imp_le])
   633 
   633 
   634 (* FIXME: the stronger version of real_root_less_iff
       
   635  breaks CauchysMeanTheorem.list_gmean_gt_iff from AFP. *)
       
   636 
       
   637 declare real_root_less_iff [simp del]
       
   638 lemma real_root_less_iff_nonneg [simp]:
       
   639   "\<lbrakk>0 < n; 0 \<le> x; 0 \<le> y\<rbrakk> \<Longrightarrow> (root n x < root n y) = (x < y)"
       
   640 by (rule real_root_less_iff)
       
   641 
       
   642 end
   634 end