Occupied squares have value 1:

0  0  0  0  0  0  0  0
0  0  0  0  0  0  0  0
0  0  0  0  0  0  0  0
0  0  0  0  0  0  0  0
0  0  0  0  0  0  0  0
0  0  0  0  0  0  1  1
0  0  1  0  0  0  1  1
0  0  1  1  0  0  0  1

Squares not under attack have value 0:

1  1  1  1  0  0  1  1
0  1  1  1  0  0  1  1
0  0  1  1  1  0  1  1
0  0  1  1  1  1  1  1
1  0  1  1  1  1  1  1
1  1  1  1  1  1  1  1
1  1  1  1  1  1  1  1
1  1  1  1  1  1  1  1

model 'dqueens'

! Description  : Dudeney's queen placement problem
! Source       : Dudeney, H.E., (1917), Amusements in Mathematics, Thomas Nelson and Sons.  
! Date written : Xpress-MP 24/10/99, Mosel 17/4/03
! Written by   : M J Chlond 

  uses 'mmxprs'
  
  parameters
    size = 8
  end-parameters
  
  declarations
    S = 1..size
    x: array(S,S) of mpvar ! x(i,j) = 1 if square {I,J} occupied, 0 otherwise
    a: array(S,S) of mpvar ! a(i,j) = 1 if square {I,J} attacked, 0 otherwise
  end-declarations

  ! minimise number of squares attacked  
  attack:= sum(i in S,j in S) a(i,j)

  ! all eight queens used
  numq:= sum(i in S,j in S) x(i,j) = 8

  ! five of original queens untouched
  sl:= sum(j in 3..size) x(8,j) + x(7,size) + x(6,size) = 5

  ! a(i,j) = 1 if square {i,j} attacked
  forall(i in S,j in S)
    att(i,j):= sum(m in S | m <> i and m-i+j >= 1 and m-i+j <= size) x(m,m-i+j)+
               sum(m in S | m <> i and i+j-m >= 1 and i+j-m <= size) x(m,i+j-m)+
               sum(m in S | m <> i) x(m,j) + sum(n in S | n <> j) x(i,n) <= 99*a(i,j) 

  forall(i in S, j in S) do
    x(i,j) is_binary
    a(i,j) is_binary
  end-do

  minimise(attack)
  
  forall(i in S) do
    forall(j in S)
      write(getsol(x(i,j)),' ')
    writeln
  end-do

end-model