I agree Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.
theory Defs imports Main begin fun sumupto :: "nat \<Rightarrow> nat" where "sumupto 0 = 0" | "sumupto (Suc n) = (Suc n) + sumupto n" end
theory Submission imports Defs begin lemma kleiner_gauss: "sumupto n = n * (n+1) div 2" sorry end
theory Check imports Submission begin lemma "sumupto n = n * (n+1) div 2" by (rule Submission.kleiner_gauss) end
theory Defs imports Main begin fun sumupto :: "nat \<Rightarrow> nat" where "sumupto 0 = 0" | "sumupto (Suc n) = (Suc n) + sumupto n" end
theory Submission imports Defs begin lemma kleiner_gauss: "sumupto n = n * (n+1) div 2" sorry end
theory Check imports Submission begin lemma "sumupto n = n * (n+1) div 2" by (rule Submission.kleiner_gauss) end