reverted e7a80c6752c9 -- there's not much point in putting a diagnosis tool (as opposed to a proof method) in Plain, but more importantly Sledgehammer must be in Main to use SMT solvers
Intro Ref System Logics HOL ZF Inductive TutorialI IsarOverview IsarRef IsarImplementation Locales LaTeXsugar Classes Codegen Functions Nitpick Main Sledgehammer