“…From left to right, the S, I, H and R populations Figure 16 Contour plots of the solution to (8) at time, above, t = 4.71 and, below, t = 4.72, roughly corresponding to 5 p.m. of the 4 th day. Above, the case with the commuters' movement (15), below the case with no movement. Apart from the spreading of the virus in the bottom left corner, the S distribution in the line above is symmetric w.r.t.…”