The LO statement identifies the SAS variable in the ARCDATA=
data set that contains the minimum feasible flow or lower flow bound for arcs in the network. If an observation contains nonarc
variable information, the LO list variable has the value of the lower bound for the nonarc variable named in the NAME
list variable. The LO list variables must have numeric values. It is not necessary to have a LO statement if the name of
this SAS variable is _LOWER_, _LO_, _LOWERBD, or _MINFLOW.