Heliosheath map of regions (light-gray areas) where in the hydrodynamic model the ratio of the 1st-to-2nd terms on the righthand side of Eq. (7) is <1/100 (lower panels) and <1/10 (upper panels); that is, the role of diffusion is small. Left column is for Bohm diffusion, case (i); right column for (κ_Bκ_ACR)^1/2, case (iii).