Before revision:  In order to strengthen the analysis of the PML, a key ingredient is to employ novel " continuity" properties of the PML distributions and construct a chain of suitable quantized PMLs, or " coverings".
After revision:  In order to strengthen the analysis of the PML, a key ingredient is to employ novel `` continuity" properties of the PML distributions and construct a chain of suitable quantized PMLs, or " coverings".