Work in progress standard library for Lean 4. This is a collection of data structures and tactics intended for use by both computer-science applications and mathematics applications of Lean 4.

• Get the newest version of elan. If you already have installed a version of Lean, you can run

  elan self update
  

  If the above command fails, or if you need to install elan, run

  curl https://raw.githubusercontent.com/leanprover/elan/master/elan-init.sh -sSf | sh
  

  If this also fails, follow the instructions under Regular install here.
• To build std4 run lake build. To build and run all tests, run make.
• If you added a new file, run the following command to update Std.lean:

  find Std -name "*.lean" | env LC_ALL=C sort | sed 's/\.lean//;s,/,.,g;s/^/import /' > Std.lean
  

  (or use scripts/updateStd.sh which contains this command).

You can generate std4's documentation with

# if you're generating documentation for the first time
> lake -Kdoc=on update
...
# actually generate the documentation
> lake -Kdoc=on build Std:docs
...
> ls build/doc/index.html
build/doc/index.html

The top-level HTML file will be located at build/doc/Std.html, though to actually expose the documentation as a server you need to

> cd build/doc
> python3 -m http.server
Serving HTTP on :: port 8000 (http://[::]:8000/) ...

Note that documentation for the latest nightly of std4 is available as part of the Mathlib 4 documentation.

The easiest way to contribute is to find a missing proof and complete it. The proof_wanted declaration documents statements that have been identified as being useful, but that have not yet been proven.