Reiteration formulae for the real interpolation method including L or R limiting spaces

Abstract

We consider a real interpolation method defined by means of slowly varying functions. We present some reiteration formulae including so called $L$ or $R$ limiting interpolation spaces. These spaces arise naturally in reiteration formulae for the limiting cases $\theta =0$ or $\theta =1$. Applications to grand and small Lorentz spaces are given.