Legal MPS?

Subject:	Legal MPS?
Date:	Thu, 28 Jan 2010 08:31:07 -0400

Hi,

Any experts here on the MPS format? I am working on some unusual
borderline cases and would like a second opinion.

1. Is it legal to have a completely empty MPS file? That is, is the
following legal:

NAME test
ROWS
COLUMNS
RHS
ENDATA

The sources I have access to are ambiguous. The ROWS and COLUMNS headers
are mandatory, but it is not clear whether any content is required. clp
accepts the file and processes it correctly, but I have seen other
solvers that do not.

2. Can one use the RANGES section to build inconsistent constraints,
such as

0 <= x1 + x2 <= -1

Thanks a lot for any pointers

gus gassmann