Models And Counter-Examples

This page is obsolete. Mace4 is now being maintained elsewhere.


Mace4 is a program that searches for finite models of first-order formulas. For a given domain size, all instances of the formulas over the domain are constructed. The result is a set of ground clauses with equality. Then, a decision procedure based on ground equational rewriting is applied. If satisfiability is detected, one or more models are printed. Mace4 is a useful complement to first-order theorem provers, with the prover searching for proofs and Mace4 looking for countermodels, and it is useful for work on finite algebras. Mace4 performs better on equational problems than our previous model-searching program Mace2.

Fun and Games: Solving Sudoku puzzles with Mace4

The Distribution Package

The current version of Mace4 for unix-like systems (July-2005) is packaged with Prover9. See the Prover9 Quickstart Page for notes on downloading and installing Mace4 and Prover9.

A previous version of Mace4 has been compiled for Microsoft Windows: (May 2004). This contains a Windows binary only (command line).



Copyrights and License

See the Otter/MACE Legal Page.

* The spice, not the weapon.

These activities are projects of the Mathematics and Computer Science Division of Argonne National Laboratory.