In a transfer of energy as heat without work being done, there are changes of entropy in both the surroundings which lose heat and the system which gains it. The increase, Δ S, of entropy in the system may be considered to consist of two parts, an increment, Δ S ′ that matches, or 'compensates', the change, −Δ S ′, of entropy in the surroundings, and a further increment, Δ S ′′ that may be considered to be 'generated' or 'produced' in the system, and is said therefore to be 'uncompensated'. Thus