Elsie Geas - Another Lazy Clause Generation Solver

What's with the name?

Well, it's an LCG solver. An Ell-Cee-Gee solver. Yeah, that's all it is. That, and the drive to implement it does have an air of compulsion to it.

Why another solver?

The compulsion to build solvers seems to be a bit of an occupational sickness.

But mostly to play around with different implementation ideas. Geas is intended to be readily extensible (with new variable types as well as propagators), can cope with large variable domains, and can spawn multiple solver instances in the same process.

How to build it?

Requirements:

• Core engine:
  • C++ compiler (g++/clang++)
• ML interface, and FZN frontend:
  • ocaml
  • camlidl

The easiest way to get camlidl is using opam.

• On OSX:

brew install ocaml opam

• or Ubuntu:

sudo apt-get install ocaml opam

Then, in either case:

opam init
eval `opam config env`
opam install camlidl

Then just call make in the root directory of the repository. This builds the Flatzinc frontend fzn/fzn_geas. Afterwards, you can also build the interactive top-level by calling make geas_top in the ml subdirectory.