“…On the interval [0, 1], we have y(x − 1, 0) � ϕ(x − 1, 0) � 0 and on the interval [1,2], we have y(x − 1, 0) � y 0 (x − 1, 0) � 0. Combining these results give y(x − 1, 0) � 0, so that equation (11) becomes zy/zt(x, 0) � g(x, 0) and since g is a smooth function, we have |y(x, 0)| ≤ C on zR, which implies that…”