My Constraint Programming Blog

G12 MiniZinc Distribution 1.5.1
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* We have added the following variants of the count/3 constraint to the MiniZinc library:

count_eq (synonym for count)
count_geq
count_gt
count_leq
count_lt
count_neq


Bugs fixed in this release:

* mzn2fzn now correctly flattens the built-in functions xorall/1 and iffall/1 when they appear in reified contexts with at least two variables and at least one literal "true" in their array argument. [Bug #340]

* A bug in mzn2fzn that caused models that were satisfiable under the relational semantics to be incorrectly flattened into unsatisfiable FlatZinc instances has been fixed. [Bug #337]

* A bug that caused mzn2fzn to infer incorrect bounds for arrays of set variables has been fixed. [Bug #341]

Posted by hakank at 08:19 PM | Permalink

Dear users, We have just released JaCoP 3.2. This is a release that fixes few bugs as well as provides an interface from Scala to JaCoP. Examples of using Scala are provided in ExamplesScala package. Additional discussion and examples are also available at

JaCoP/Scala and at Hakan Kjellerstand blog at A first look at scalaJaCoP (Scala wrapper for JaCoP)

best regards,

Core Developer Team

Posted by hakank at 05:45 PM | Permalink

The Challenge

The aim of the challenge is to start to compare various constraint solving technology on the same problems sets. The focus is on finite domain propagation solvers. An auxiliary aim is to build up a library of interesting problem models, which can be used to compare solvers and solving technologies.

Entrants to the challenge provide a FlatZinc solver and global constraint definitions specialized for their solver. Each solver is run on 100 MiniZinc model instances. We run the translator mzn2fzn on the MiniZinc model and instance using the provided global constraint definitions to create a FlatZinc file. The FlatZinc file is input to the provided solver. Points are awarded for solving problems, speed of solution, and goodness of solutions (for optimization problems).

...

Dates

• Registration opens: 1 May 2012.
• Problem submission deadline: 12 July 2012.
• Initial submission round begins: 1 August 2012.
• Initial submission round ends: 20 August 2012.
• Final submissions: 1 September 2012.
• Announcement of results at CP2012: 8-12 October 2012.

Posted by hakank at 08:27 PM | Permalink