“…Recalling again that for these boundaries, we do not impose the reduced PDE (although many of the 2nd order derivative terms in (5) vanish once v, r ↓ 0). The system of SDEs (2) for v and r in (2) are of the same type and, thus, also the 1st-and 2nd-order derivatives ∂u ∂r , ∂ 2 u ∂r 2 and their coefficients in the PDE (5) are of the same form as for v. Therefore, at r ↓ 0, the HCIR model has degeneracy and no side condition is prescribed. Therefore, the obtained equations at such boundaries are taken into account for the boundary nodes.…”