The LP procedure treats missing values as missing in all
rows except those that identify either upper or lower bounds
on structural variables. If the row is an upper-bound row,
then the type identifier is UPPERBD and the LP procedure
values as +INFINITY. If the row is a lower-bound row, then
the type identifier is LOWERBD and the LP procedure treats the missing
values as 0, except for the variables that are identified as UNRSTRCT.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.