In the previous case, we narrowed down the set of three f -bond diagrams by considering only the monomers local to a site there the two polymer species are spatially close (using the θ s,s function). However, we will now consider the possibility that the flanking monomers are also nearby to their counterparts on the opposing chain. We then will need to consider a less local set of correlations, extending further down the two chains for at least another monomer pair. We will distinguish these scenarios by the number of sequential paired charges, writing this with the following: