Take the following as truth: In order for the discount to remain unchanged when Pb is changed, the price of the workshare category must be changed in an amount exactly equal to gDPb, as made clear by Equation (4).
Then the following statement: "In order for the discount to remain unchanged when Pb is changed, the price of the workshare category must be changed in an amount exactly equal to gDPb" is true, false, or inconclusive?