```! Lottery ticket covering problem. Which combination of tickets should we buy so we win, regardless of the outcome. Cast in the form of betting on the outcome of a number of futbol games. Ref: Linderoth, J., F. Margot, ang G. Thain(2009), "Improving Bounds on the Football Pool Problem by Integer Programming and High-Throughput Computing", INFORMS Journal of Computing, vol. 21, no. 3, pp. 445-457; SETS: OUTK1; OUTK2; OUTK3; OUTK4; OUTK5; OUTK6; COMBO( OUTK1,OUTK2,OUTK3,OUTK4,OUTK5,OUTK6): Y; ENDSETSDATA: OUTK1 = WIN LOSE DRAW; OUTK2 = WIN LOSE DRAW; OUTK3 = WIN LOSE DRAW; OUTK4 = WIN LOSE DRAW; OUTK5 = WIN LOSE DRAW; OUTK6 = WIN ;!LOSE DRAW; ENDDATA ! Known results: # Games Tickets must buy 1 1 2 3 3 5 4 9 5 27 6 71<= t <= 73 ; ! Y(i1, i2, i3, i4, i5, i6) = 1 if we buy a ticket that bets on outcome (i1, i2, i3, i4, i5, i6); MIN = @SUM( COMBO(i1, i2, i3, i4, i5, i6): Y(i1, i2, i3, i4, i5, i6)); ! Make them binary; ! @FOR( COMBO(i1, i2, i3, i4, i5, i6): @BIN(Y(i1, i2, i3, i4, i5, i6))); ! For each game and each outcome, at least one of our choices must be close enough. We are close enough if we got only one wrong; @FOR( COMBO( i1, i2, i3, i4, i5, i6): Y( i1, i2, i3, i4, i5, i6) ! Get all right; ! or get exactly 1 outcome wrong ; +@SUM( COMBO(k1, i2, i3, i4, i5, i6) | k1 #NE# i1 : Y(k1, i2, i3, i4, i5, i6)) +@SUM( COMBO(i1, k2, i3, i4, i5, i6) | k2 #NE# i2 : Y(i1, k2, i3, i4, i5, i6)) +@SUM( COMBO(i1, i2, k3, i4, i5, i6) | k3 #NE# i3 : Y(i1, i2, k3, i4, i5, i6)) +@SUM( COMBO(i1, i2, i3, k4, i5, i6) | k4 #NE# i4 : Y(i1, i2, i3, k4, i5, i6)) +@SUM( COMBO(i1, i2, i3, i4, k5, i6) | k5 #NE# i5 : Y(i1, i2, i3, i4, k5, i6)) >= 1; ); ! Kill some symmetry; Y(1, 1, 1, 1, 1, 1) = 1;```