the class of components which includes diesel and petrol engines
the ratio of the amount of air in a reaction to the amount of ruel
the emissions index of the internal combustion engine
(Forall (?Self ?Time) (<=> (Active ?Time Internal-Combustion-Engine ?Self) (And (Internal-Combustion-Engine ?Self) (Active ?Time Reciprocating-Component ?Self) (Active ?Time Work-Producing-Component ?Self)))) (=> (Internal-Combustion-Engine ?Self) (Quantity.Dimension (Air-Fuel-Ratio ?Self) Dimensionless))