4LCLQYKMQSLNHY47BPLR5BULPHFPN3KR3RPK2YIORUKFWIVKJOXQC
const CCTK_REAL rtol = 0.0;
const CCTK_REAL atol = 1.0e-12;
const CCTK_REAL maxerr = mlmg.solve(sols, rhss, rtol, atol);
// const CCTK_REAL rtol = 0.0;
// const CCTK_REAL atol = 1.0e-12;
const CCTK_REAL maxerr = mlmg.solve(sols, rhss, reltol, abstol);