An example of estimation of binding site covalence. The binding site covalence between novel and known reactions belonging to rule number 1 (rule id F.C.1) is evaluated. The largest binding site, a compound contains, is shown near by the compound. Hereby, b
means system name step in common for reaction f and g while b
means system name steps of a novel reaction f and a known reaction g, respectively. The superscript s and p means substrate side and product side, respectively. XB is the binding site covalence between a novel reaction f and a known reaction g. (Equation 1a).