doc-src/TutorialI/Misc/Plus.thy
author wenzelm
Tue, 14 Oct 2008 15:16:11 +0200
changeset 28586 d238b83ba3fc
parent 27015 f8537d69f514
permissions -rw-r--r--
renamed kill_all to kill, in conformance with atp_kill command; simplified/unified treatment of preferences; check_thread_manager: CRITICAL due to global ref; goal addressing via Thm.cprem_of; reduced NJ basis library stuff to bare minimum;

(*<*)
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
(*>*)