This package contains a few sample databases for the Metamath
language. You can read them and discover the proof they bring, or you
can add your own proofs of other mathematical statements.

Check out in particular the file set.mm, which contain many modern
mathematical results proved al the way from the axioms of set
theory. A graphical and interactively browsable rendition of the same
database is available as the Metamath Proof Explorer[1].

 [1] http://us.metamath.org/mpeuni/mmset.html

You can check the correctness of a Metamath database using the
metamath program (contained in the metamath package). For example, to
check that the file set.mm is correct you can use:

  $ metamath 'read "/usr/share/metamath/databases/set.mm"' 'verify proof *' 'exit'

Using the same program you can edit the proofs or add new theorems and
their proofs. Please check out the book "Metamath, A Computer Language
for Pure Mathematics"[2], by Norman Megill, for more information on
how to use the program and on the Metamath language itself.

 [2] http://us.metamath.org/downloads/metamath.pdf

See also the Metamath website[3] to learn more about Metamath and its
community. If you'd like to contribute your proofs to the Metamath
project, please read the file CONTRIBUTING.md and get in touch with
the community.

 [3] http://us.metamath.org/
