\ LP file for the 2x4 example, created by POLYOMINO_LP_WRITE.

Maximize
  Obj: 0
Subject to
 x1 + x9 + x15 + x17 + x19 = 1
 x2 + x9 + x10 + x15 + x16 + x18 + x19 + x20 = 1
 x3 + x9 + x10 + x13 + x15 + x16 + x19 + x20 = 1
 x4 + x10 + x14 + x16 + x20 = 1
 x5 + x11 + x13 + x15 + x17 = 1
 x6 + x11 + x12 + x13 + x14 + x16 + x17 + x18 = 1
 x7 + x11 + x12 + x13 + x14 + x17 + x18 + x19 = 1
 x8 + x12 + x14 + x18 + x20 = 1
 x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 = 1
 x9 + x10 + x11 + x12 = 1
 x13 + x14 + x15 + x16 + x17 + x18 + x19 + x20 = 1
 x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + 3 x9 + 3 x10 + 3 x11 + 3 x12 + 4 x13
   + 4 x14 + 4 x15 + 4 x16 + 4 x17 + 4 x18 + 4 x19 + 4 x20 = 8
Binary
  x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15 x16 x17 x18 x19 x20
End