GP/PARI CALCULATOR Version 2.8.0 (development 19698-ef4bb1d)

          amd64 running linux (x86-64/GMP-5.1.3 kernel) 64-bit version

    compiled: Oct 19 2016, gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.3)

                            threading engine: single

                 (readline v6.3 enabled, extended help enabled)

                     Copyright (C) 2000-2016 The PARI Group

PARI/GP is free software, covered by the GNU General Public License, and comes 

WITHOUT ANY WARRANTY WHATSOEVER.

Type ? for help, \q to quit.

Type ?15 for how to get moral (and possibly technical) support.

parisize = 8000000, primelimit = 500000

? default(realprecision,1000)

? pol=x^7 - 658

%2 = x^7 - 658

? allocatemem(2^32)

  ***   Warning: new stack size = 4294967296 (4096.000 Mbytes).

? bnf=bnfinit(subst(pol,x,y),1);

? B=[[56, 0, 0, 0, 0, 0, 0; 0, 4, 0, 0, 0, 0, 0; 0, 0, 4, 0, 0, 0, 0; 0, 0, 0, 4, 0, 0, 0; 0, 0, 0, 0, 4, 0, 0; 0, 0, 0, 0, 0, 4, 0; 0, 0, 0, 0, 0, 0, 4], [1]];