!Keyword: market equilibrium;
MAX  9X1 + 4.5X2 + 3X3 + 2.25X4   ! Maximize broker's revenue
   -  A1 - 2A2   - 3A3 - 4A4      ! minus cost
SUBJECT TO
   A1 + A2 + A3 + A4 - X1 - X2 - X3 - X4 = 0  ! Supply = demand
   A1 <= 2   A2 <= 2   A3 <= 2    A4 <= 2     ! Steps in supply
   X1 <= 2   X2 <= 2   X3 <= 2    X4 <= 2     ! and demand functions
END
