society would decrease, because it would have to expend more labor-time on the production of the same stock of use-values.
Fourth case. Let the labor-time required for the production of A and B rise and fall, but not uniformly; that is to say, the labor-time required for the production of A may rise, while that required for B may fall, or vice versa. All of which can be reduced to the simple case where the labor-time required for the production of one commodity remains unchanged, while that required for the other rises or falls.
The exchange value of any commodity is expressed in the use-value of any other commodity, be it in integral units or in fractions thereof. As exchange value, every commodity is capable of subdivision, like the labor-time embodied in it. The equivalence of commodities is independent of their physical divisibility as use-values, just as the sum of the exchange values of commodities is indifferent to the change of form which use-values have to undergo when converted into a single new commodity.