## Version 1.2.0

This subroutine performs iterative reﬁnement and provides information on the error in the resulting solution of a set of $n$ sparse linear equations $Ax=b$, either as an upper bound on the actual error (forward error) or as a bound on the perturbation to the matrix elements which would make the solution obtained the exact solution of a perturbed problem with the same sparsity pattern as the original matrix (backward error). All estimates are provided in the $\infty$-norm, that is $||x|{|}_{\infty }=\underset{i}{max}|{x}_{i}|$.