[{"data":1,"prerenderedAt":4},["ShallowReactive",2],{"RTqPfNNRA8":3},"# Interactive Theorem Proving course\n\nThis is a course on Interactive Theorem Proving with Lean 4.\n\n## Main features\n\n- Our main focus is on the _foundations_ of Lean. We discuss the key ideas\nof the underlying type theory in a semi-formal way, aiming to provide some\nintuition on the inner workings.\n\n- We follow a _bottom-up_ approach, aiming to introduce each feature of Lean\nbefore using it. We make a few exceptions in our examples when we feel that\nthe reader should still be able to intuitively understand the features we\nuse, even when we have not yet formally introduced them.\n\n- The course material is divided by _topic_ rather than by _lesson_. Some\nfiles are therefore significantly longer than others.\n\n- We suggest _exercises_ on each topic.\n\n## How to get started with Lean 4\n\nThe material in this course can be used in several alternative ways:\n\n- Use Lean 4 in your browser _right now_ via [Lean 4 web][lean4web]. Choose\nthis if you are in a hurry and do not have time to do a proper installation.\n(Remember to save your code locally before closing the web page.)\n\n- Install [Lean 4][localInstall] locally on your own computer. Following the\ninstructions requires some time and patience, as well as some free disk\nspace (~15GB should be enough). Probably the best choice, once it is set up.\n\n- Use [GitHub codespaces][codespaces] on this repository. A full Lean 4\nremote server will be automatically set up for you, and you will be able to\nwork in your browser _and_ save your changes. Almost as good as a local\ninstallation. Currently (in 2025) GitHub gives you 60 server hours for free\neach month (more if you become a verified student). (Note that saved but\n_uncommitted_ changes will be lost if a codespace is inactive for more than\n30 days.)\n\n  [![Open in GitHub Codespaces](https://github.com/codespaces/badge.svg)](https://codespaces.new/RobertoZunino/ITPCourse?quickstart=1)\n\n[lean4web]: https://live.lean-lang.org/\n[localInstall]: https://lean-lang.org/install/\n[codespaces]: https://github.com/codespaces\n\n## Lean 4 documentation\n\n- [Lean Language Reference][lean4ref] -- the ultimate authority on Lean\n  syntax, features, and tactics.\n- [Mathlib4 Documentation][mathlibDoc] -- the standard library formalizing\n  large areas of mathematics.\n- [Theorem Proving in Lean 4][thProving] -- a convenient tutorial.\n- [Mathematics in Lean][mil] -- a book on how to formalize mathematics in\n  Lean.\n- [Loogle][loogle] -- a search engine for the Lean libraries, based on\n  _formulas_.\n- [LeanSearch][leansearch] -- a search engine for the Lean libraries, based\n  on _natural language_.\n- [Cheatsheet][cheatsheet] -- a summary of the most common terms and tactics.\n- [100 theorems][th100list] -- a list of famous results.\n- [Lean Game Server][leanGames] -- browser games involving Lean proofs.\n\n[lean4ref]: https://lean-lang.org/doc/reference/latest/\n[mathlibDoc]: https://leanprover-community.github.io/mathlib4_docs/\n[thProving]: https://lean-lang.org/theorem_proving_in_lean4/\n[mil]: https://leanprover-community.github.io/mathematics_in_lean/index.html\n[loogle]: https://loogle.lean-lang.org/\n[leansearch]: https://leansearch.net/\n[cheatsheet]: Cheatsheet.md\n[th100list]: https://leanprover-community.github.io/100.html\n[leanGames]: https://adam.math.hhu.de/",1780846773360]