SLICOT license situation

[Andrew Janke]

Hi, Debian Science maintainers,

What's the situation with the license for the SLICOT library included in 
Debian?

According to https://packages.debian.org/source/stable/slicot, Debian is 
shipping SLICOT 5.0. But according to 
http://slicot.org/the-control-and-systems-library-slicot/source-archives, 
only the SLICOT 4.x series is licensed under the GPL. The SLICOT 5.x 
series is only available under commercial or academic-use-only licenses, 
which isn't GNU compatible or a Free software license. Is it appropriate 
to be shipping SLICOT 5.x in Debian? Should it go in the non-free 
category, at least?

I checked the debian-legal mailing list history 
(https://www.google.com/search?as_q=debian-legal+slicot&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=lists.debian.org&as_occt=any&safe=images&as_filetype=&as_rights=, 
as suggested by 
https://wiki.debian.org/DFSGLicenses#If_the_license_isn.27t_on_this_list), 
and didn't see any mention of SLICOT.

Cheers,
Andrew Janke