“…Finally, we consider additional "two-points pharmacophore" versions of the kernels (15), (16) and (17), based on pairs, instead of triplets, of atoms (19). Letting T 2 be the set of all possible two-points pharmacophores, that is, pairs of atom types together with the bin index of the edge connecting them, and φ 2pt 0 (m) = (φ t,0 (m)) t∈T2 and φ 2pt 1 (m) = (φ t,1 (m)) t∈T2 be the mappings of the molecule m to T 2 , corresponding to φ 3pt 0 (m) and φ 3pt 1 (m), we define the three following kernels.…”