This is "fzn-oscar-cbls", a MiniZinc backend using the Oscar/CBLS
solver. It solves problems by using constraint-based local search in
an adaptive tabu search setting. Before running the search, the
backend looks for one-way constraints that can be implemented by
invariants and for implicit constraints that can be maintained during
search through specific neighbourhoods. During search the backend
performs propagation, using some parts of OscaR/CP, to reduce the size
of the search space.  The backend sometimes makes use of compound-move
generation (CMG), as described in [BFP19], on models that have
certain model structures. This is an experimental feature.


This backend has been described more in depth in [BMFP15] and has been
first developed as part of Gustav Björdal's bachelor thesis [Bjö14].
More info on OscaR can be found at http://www.oscarlib.org. The CBLS
engine of OscaR is developed at CETIC, Belgium, by Renaud De
Landtsheer, Yoann Guyot, and Gustavo Ospina. OscaR is free software
and distributed under the terms of the LGPL v2.1.



This entry to the MiniZinc Challenge 2020 is submitted by:

Gustav Björdal (Uppsala University, Sweden)
Jean-Noël Monette (Tacton Systems AB, Sweden)
Pierre Flener (Uppsala University, Sweden)
Justin Pearson (Uppsala University, Sweden)
http://www.it.uu.se/research/group/astra/

and 

Renaud De Landtsheer (CETIC research centre, Belgium)
Gustavo Ospina (CETIC research centre, Belgium)
https://www.cetic.be/


[BFP19] G. Björdal, P. Flener, and J. Pearson. Generating compound
moves in local search by hybridisation with complete search. In: L.-M.
Rousseau and K. Stergiou (editors), CP-AI-OR 2019. Lecture Notes in
Computer Science, volume 11494, pages 95-111. Springer, 2019.

[BMFP15] G. Björdal, J.-N. Monette, P. Flener, and J. Pearson. A
constraint-based local search backend for MiniZinc. Constraints,
journal fast track of CP-AI-OR 2015, 20(3):325-345, July
2015. (http://dx.doi.org/10.1007/s10601-015-9184-z)

[Bjö14] G. Björdal: The First Constraint-Based Local Search Backend
for MiniZinc. Bachelor Thesis in Computer Science, Report IT 14 066,
Faculty of Science and Technology. Uppsala University, Sweden,
2014. (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-234847)