add lemmas of_real_eq_star_of, Reals_eq_Standard
authorhuffman
Wed, 27 Sep 2006 05:58:42 +0200
changeset 20729 1b45c35c4e85
parent 20728 8d21108bc6dd
child 20730 da903f59e9ba
add lemmas of_real_eq_star_of, Reals_eq_Standard
src/HOL/Hyperreal/HyperDef.thy
src/HOL/Hyperreal/NSA.thy
--- a/src/HOL/Hyperreal/HyperDef.thy	Wed Sep 27 05:39:29 2006 +0200
+++ b/src/HOL/Hyperreal/HyperDef.thy	Wed Sep 27 05:58:42 2006 +0200
@@ -84,6 +84,16 @@
 lemma star_of_of_real [simp]: "star_of (of_real r) = of_real r"
 by transfer (rule refl)
 
+lemma of_real_eq_star_of [simp]: "of_real = star_of"
+proof
+  fix r :: real
+  show "of_real r = star_of r"
+    by transfer simp
+qed
+
+lemma Reals_eq_Standard: "(Reals :: hypreal set) = Standard"
+by (simp add: Reals_def Standard_def of_real_eq_star_of)
+
 
 subsection{*Existence of Free Ultrafilter over the Naturals*}
 
--- a/src/HOL/Hyperreal/NSA.thy	Wed Sep 27 05:39:29 2006 +0200
+++ b/src/HOL/Hyperreal/NSA.thy	Wed Sep 27 05:58:42 2006 +0200
@@ -46,17 +46,8 @@
 const_syntax (HTML output)
   approx  (infixl "\<approx>" 50)
 
-
-lemma hypreal_of_real_of_real_eq: "hypreal_of_real r = of_real r"
-proof -
-  have "hypreal_of_real r = hypreal_of_real (of_real r)" by simp
-  also have "\<dots> = of_real r" by (rule star_of_of_real)
-  finally show ?thesis .
-qed
-
 lemma SReal_def: "Reals == {x. \<exists>r. x = hypreal_of_real r}"
-by (simp add: Reals_def image_def hypreal_of_real_of_real_eq)
-
+by (simp add: Reals_def image_def)
 
 subsection {* Nonstandard Extension of the Norm Function *}