!ENCE 724/BMGT 832, Min Cost Flow LP, LINDO formulation, Version 1
!Dr. Steven A. Gabriel
!
minimize 100x12+50x13+75x23+60x24+90x34 !Total cost of flow
s.t. 
x12+x13=3      !Node 1: conservation of flow
x12-x23-x24=0  !Node 2: conservation of flow
x13+x23-x34=0  !Node 3: conservation of flow
x24+x34=3      !Node 4: conservation of flow
end
! nonnegative variables assumed