doc-src/TutorialI/Misc/Plus.thy
author wenzelm
Tue, 21 Jul 2009 20:37:31 +0200
changeset 32102 81d03a29980c
parent 27015 f8537d69f514
permissions -rw-r--r--
added worker_group; fork: default to subgroup of worker_group; removed obsolete fork_local; join/get_result: cumulative flattened exceptions; map: subgroup of worker_group;

(*<*)
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
(*>*)