To estimate the hypothesis for the mechanism of the non-zero offset, we performed numerical simulations using a reaction-diffusion model that considered differences in the cleavage rate of linker DNAs (see Supplemental Note S2). First, we changed the hybridization and the strand displacement rates for L † AB cleavage. Next, we varied the threshold parameters KAB and KAC for rdiv_B and rdiv_C (Eqs. S.90 and S.91 in Supplemental Note S2); the larger the threshold parameters, the faster the division.