Graded, vertically indecomposable lattices of n=21 elements and c=2 coatoms.

Author:      Jukka Kohonen
Date:	     2018-07-14
Affiliation: University of Helsinki
E-mail:      jukka.kohonen@iki.fi

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00README.txt     This file
checksum.md5     MD5 checksums of the uncompressed digraph6 files
lat.gra21.2.xz   Graded vi-lattices (n=21, c=2)

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All lattice listings are in the following format:

1) Top and bottom have been removed.  To restore them, add a top above
the maximal elements, and a bottom below the minimal elements.

2) The graphs are stored in the digraph6 format (machine-readable, one
lattice per line), see <http://pallini.di.uniroma1.it/Guide.html>.

3) Finally they are compressed with xz, see <https://tukaani.org/xz/>.