Auxiliary routines Node5 la_lin_berr:    backward error Node3 lacn2:          1-norm estimate, e.g., || A^ {-1} ||_1 in gecon Node4 lacon:          1-norm estimate, e.g., || A^ {-1} ||_1 in gecon, old Node1 Auxiliary routines Node1->Node5 Node1->Node3 Node1->Node4 Node2 Linear solve, AX = B Node2->Node1 .