The NEOS Server offers ICOS for the solution of continuous, numerical constraint satisfaction problems and global optimization problems formulated in scalar AMPL format.

ICOS uses linear relaxations, filtering methods, and interval arithmetic to determine the solutions of the given problem. Default options are used. For some background see the papers by the author Yahia Lebbah. For the optimization version, see here.

This solver was implemented by Hans Mittelmann and executes at

Using the NEOS Server for ICOS

The user must submit a problem in AMPL format. Examples of models in AMPL format can be found in the ICOS distribution. The numbers of variables and constraints should be moderate.

Different from full AMPL, the submitted file should contain a self-contained model in scalar format, no data file or other commands. See here and the sample submission problems.

Using the NEOS Server for icos/AMPL

The user must submit a model in AMPL format. Examples are provided in the examples section of the AMPL website.

The problem must be specified in a model file. A data file and commands files may also be provided. If the commands file is specified, it must contain the AMPL solve command; however, it must not contain the model or data commands. The model and data files are renamed internally by NEOS.

The commands file may include option settings for the solver. To specify solver options, add

  option icos_options 'OPTIONS';
where OPTIONS is a list of one or more of the available solver options for AMPL.

Web Submission Form
AMPL model for satisfiability problem (scalar format, no comands)
AMPL model for global optimization problem (scalar format, no comands)
Additional Settings

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Please do not click the 'Submit to NEOS' button more than once.