# HG changeset patch # User paulson # Date 1254411773 -3600 # Node ID 45fa9254ddc815261615c1ffb096582806234e18 # Parent 02f412281b99f03f8372473919f16832522780de Proved a new theorem: nat_to_nat2_inj diff -r 02f412281b99 -r 45fa9254ddc8 src/HOL/Library/Nat_Int_Bij.thy --- a/src/HOL/Library/Nat_Int_Bij.thy Thu Oct 01 15:19:49 2009 +0200 +++ b/src/HOL/Library/Nat_Int_Bij.thy Thu Oct 01 16:42:53 2009 +0100 @@ -128,6 +128,9 @@ thus "\y. \x. y = nat2_to_nat x" by fast qed +lemma nat_to_nat2_inj: "inj nat_to_nat2" + by (simp add: nat_to_nat2_def surj_imp_inj_inv nat2_to_nat_surj) + subsection{* A bijection between @{text "\"} and @{text "\"} *}