!Keyword: fleet routing, networks, airlines;
! Fleet routing with a single plane type;
!  Minimize number of planes on ground overnight;
MIN  GC2400 + GD2400 + GL2400
 ST
! The plane (old) conservation constraints;
! Chicago at 8 am,  sources - uses = 0;
 + GC2400 - F221 - F223 - F105 - F259 - GC1400 = 0
! Chicago at midnight;
 GC1400 + F228 + F230 + F412+ F238 - GC2400 = 0
! Denver at 11 am;
 GD2400 + F221 + F223 - F228 - GD1100 = 0
! Denver at high noon;
 GD1100 + F274 - F230 - F293 - F238 - GD1800 = 0
! Denver at midnight;
 GD1800 + F766 - GD2400 = 0
! LA at 8 am;
 GL2400 - F274 - GL0800 = 0
! LA  at 1400;
 GL0800 + F105 - F412 - GL1400 = 0
! LA  at 1600;
 GL1400 + F293 - F766 - GL1600 = 0
! LA  at midnight;
 GL1600 + F259 - GL2400 = 0
! Cover our flights constraints;
 F221 = 1;
 F223 = 1;
 F274 = 1;
 F105 = 1;
 F228 = 1;
 F230 = 1;
 F259 = 1;
 F293 = 1;
 F412 = 1;
 F766 = 1;
 F238 = 1;
END

