src/HOL/NthRoot.thy
changeset 62381 a6479cb85944
parent 62347 2230b7047376
child 62393 a620a8756b7c
equal deleted inserted replaced
62379:340738057c8c 62381:a6479cb85944
   402 lemma real_sqrt_le_iff [simp]: "(sqrt x \<le> sqrt y) = (x \<le> y)"
   402 lemma real_sqrt_le_iff [simp]: "(sqrt x \<le> sqrt y) = (x \<le> y)"
   403 unfolding sqrt_def by (rule real_root_le_iff [OF pos2])
   403 unfolding sqrt_def by (rule real_root_le_iff [OF pos2])
   404 
   404 
   405 lemma real_sqrt_eq_iff [simp]: "(sqrt x = sqrt y) = (x = y)"
   405 lemma real_sqrt_eq_iff [simp]: "(sqrt x = sqrt y) = (x = y)"
   406 unfolding sqrt_def by (rule real_root_eq_iff [OF pos2])
   406 unfolding sqrt_def by (rule real_root_eq_iff [OF pos2])
       
   407 
       
   408 lemma real_less_lsqrt: "0 \<le> x \<Longrightarrow> 0 \<le> y \<Longrightarrow> x < y\<^sup>2 \<Longrightarrow> sqrt x < y"
       
   409   using real_sqrt_less_iff[of x "y\<^sup>2"] by simp
   407 
   410 
   408 lemma real_le_lsqrt: "0 \<le> x \<Longrightarrow> 0 \<le> y \<Longrightarrow> x \<le> y\<^sup>2 \<Longrightarrow> sqrt x \<le> y"
   411 lemma real_le_lsqrt: "0 \<le> x \<Longrightarrow> 0 \<le> y \<Longrightarrow> x \<le> y\<^sup>2 \<Longrightarrow> sqrt x \<le> y"
   409   using real_sqrt_le_iff[of x "y\<^sup>2"] by simp
   412   using real_sqrt_le_iff[of x "y\<^sup>2"] by simp
   410 
   413 
   411 lemma real_le_rsqrt: "x\<^sup>2 \<le> y \<Longrightarrow> x \<le> sqrt y"
   414 lemma real_le_rsqrt: "x\<^sup>2 \<le> y \<Longrightarrow> x \<le> sqrt y"