 This result is because X controls all three products which are the only substitutes of A.Thus, X knows that even if its increase in price of A will generate some substitution, a significant share of these consumers will end up buying other products which he controls, therefore overall, his profits will not be reduced but rather increased.If we had found that such an increase would not have been profitable, we should further include new products which we may imagine are substitutes in a third phase until we arrive at a situation in which such an increase in price would have been profitable, indicating that those products do constitute a relevant market.