The HOL Light theorem prover

HOL Light is a computer program written by John Harrison to help users prove interesting mathematical theorems completely formally in higher order logic. It sets a very exacting standard of correctness, but provides a number of automated tools and pre-proved mathematical theorems (e.g. about arithmetic, basic set theory and real analysis) to save the user work. It is also fully programmable, so users can extend it with new theorems and inference rules without compromising its soundness. There are a number of versions of HOL, going back to Mike Gordon’s work in the early 80s. Compared with other HOL systems, HOL Light uses a much simpler logical core and has little legacy code, giving the system a simple and uncluttered feel. Despite its simplicity, it offers theorem proving power comparable to, and in some areas greater than, other versions of HOL, and has been used for some significant industrial-scale verification applications.

How to install

HOL Light is hosted on Github so you can get the sources from the Github repository. You can browse individual source files online, or check out all the code using git. The following command will copy all the code from the Github repository into a new directory hol-light (assumed not to exist already):

git clone https://github.com/jrh13/hol-light.git

HOL Light is written in Objective CAML (OCaml), and it should work with any reasonably recent version. See the README file in the distribution for detailed installation instructions.

You can also install official releases of HOL Light from OPAM.

opam install hol_light
# To compile the core module of HOL Light and use, add hol_light_module
opam install hol_light hol_light_module 

Available documentation and resources

Applications of HOL Light