doc-src/TutorialI/Misc/Plus.thy
author nipkow
Fri, 05 Jul 2002 17:48:05 +0200
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(*<*)
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theory Plus = Main:
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(*>*)
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text{*\noindent Define the following addition function *}
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consts plus :: "nat \<Rightarrow> nat \<Rightarrow> nat"
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primrec
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"plus m 0 = m"
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"plus m (Suc n) = plus (Suc m) n"
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text{*\noindent and prove*}
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(*<*)
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lemma [simp]: "!m. plus m n = m+n"
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apply(induct_tac n)
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by(auto)
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(*>*)
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lemma "plus m n = m+n"
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(*<*)
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by(simp)
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end
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(*>*)