The phrase "cannot be reduced further" is correct and can be used in written English.
For example, "The sentence has been simplified as much as possible and cannot be reduced further."
Policy interest rates cannot be reduced further.
So Japanese monetary policy is trapped in two important respects: nominal interest rates cannot be reduced further, and nor can the spot value of the yen go down in the foreign exchanges.But it is the yen's forward value, and not the spot value, which is too high.
Hence, for larger, the delay cannot be reduced further.
Due to the statistical bias of comparing data samples with very different sizes and variances (76 samples versus 11 samples), the error cannot be reduced further.
Energy dissipation per device per operation cannot be reduced further than KTln2, rather it is possible only if the computation the operation is done based on reversible principle due to fundamental thermodynamic reasons.
The proposed channel selection mechanism has an irreducible prediction error variance, (sigma _{mathbf {e}}^{2}), which cannot be reduced further and is a function of the threshold that is used by the energy detector at the decision stage.
Could the number of warheads be reduced further?
However, front driven bicycles have the disadvantage that the front driving induces unwanted steering and that the frontal area of the bicycle cannot be reduced any further.
I will also explain why I believe that the Fed still has powerful tools at its disposal to fight the financial crisis and the economic downturn, even though the overnight federal funds rate cannot be reduced meaningfully further.
The total energy price comprises the module cost, as well as the administrative, marketing, labor, installation, and the balance of system costs, some of which cannot be reduced any further.
If a subRAF cannot be reduced any further without losing the RAF property, it is referred to as an irreducible RAF (irrRAF) set.
