doc-src/TutorialI/Misc/Plus.thy
author wenzelm
Sat, 20 Aug 2011 19:21:03 +0200
changeset 44333 cc53ce50f738
parent 27015 f8537d69f514
permissions -rw-r--r--
reverted to join_bodies/join_proofs based on fold_body_thms to regain performance (escpecially of HOL-Proofs) -- see also aa9c1e9ef2ce and 4e2abb045eac;

(*<*)
theory Plus imports Main begin
(*>*)

text{*\noindent Define the following addition function *}

primrec add :: "nat \<Rightarrow> nat \<Rightarrow> nat" where
"add m 0 = m" |
"add m (Suc n) = add (Suc m) n"

text{*\noindent and prove*}
(*<*)
lemma [simp]: "!m. add m n = m+n"
apply(induct_tac n)
by(auto)
(*>*)
lemma "add m n = m+n"
(*<*)
by(simp)

end
(*>*)