Error bounds on the solution and a condition estimate are also provided.
If the reciprocal of the condition number is less than machine precision, steps 4-6 are skipped. The system of equations is solved for X using the factored form of A. 5. Iterative refinement is applied to improve the computed solution matrix and calculate error bounds and backward error estimates for it. The factorization has been completed, but the factor U is exactly singular, so the solution and error bounds could not be computed.