  A paradigm case where a limiting reduction of the form \(\mathbf{R}\) rather straightforwardly holds is that of classical Newtonian particle mechanics (NM) and the special theory of relativity (SR). In the limit where \((v/c)^2\rightarrow 0\), SR reduces to NM. Nickles says “epitomizing [the intertheoretic reduction of SR to NM] is the reduction of the Einsteinian formula for momentum,