nag_dsprfs (f07phc) Example Program Results Solution(s) 1 2 1 -4.0000 1.0000 2 -1.0000 4.0000 3 2.0000 3.0000 4 5.0000 2.0000 Backward errors (machine-dependent) 5.7e-17 1.0e-16 Estimated forward error bounds (machine-dependent) 2.3e-14 3.4e-14