Data format
The interface of 4ti2 is minimalistic: A project is defined via a set of text files with the same basename and different extensions, most importantly the file 'foo.mat' containing the problem matrix. Each of the files has a very simple format, Computed sets such as a Graver basis or a Markov basis are then written into files 'foo.gra' and 'foo.mar', respectively.

Input files and output files usually contain a matrix or a list of vectors (written as a matrix) in a standard encoding such as

2 4
1 1 1 1
1 2 3 4

There are only few exceptions, for example in a file 'foo.vars' containing user specified variable names:

3
a b x