In general let J be a column with a surplus and I the set of rows containing the non-negative assigned elements of J. Then we use the minimum of IJ to determine delta and subtract delta from I, - delta from J. Accomplishing somewhat the same objective as the transformation above is the compression subroutine of Flood [14, 261]. With this device for avoiding negative solutions, the techniques of the informal version seldom lead to a negative solution. If they should, one can always eliminate the negative solution.