  We have recently shown that at the Event Horizon of a Schwarzschild BH, the
Kruskal derivative assumes a form du/dv = +,- f(r,t)/f(r,t) = +, - 1.
Corespondingly, du^2 = dv^2, and the geodesic of a material particle becomes
NULL at the EH. Physically this means that the free fall speed measured by the
Kruskal observer V=1 at the EH. However, Tereno has difficulty in accepting
this limiting value of du/dv=1. We point out that Eq.(4) of his paper shows
(1-2M/r) dt/dr =-1, at r=2M, and, indeed, the mod of V=1. However, rather than
accepting this, Tereno has obtained and incorrect expression for t=t(r) and has
tried to find V graphically. We point out that, instead, if he uses the correct
t=t(r) relation by using Eq. (12.2.24) of Shapiro and Teukolsky, he would
indeed find V=1. It is simple to understand, physically, why one must have V=1
at the EH. If the free fall speed measured by the static Sch. Observer is Vs
and the relative velocity of the other observer is Vso with respect to the Sch.
observer, then the velocity of free fall of the test particle, V, can be found
by using the Special Relativistic velocity addition formula (locally). Since Vs
=1 at r=2M, one would always find, V=1 too. We shall not respond to any further
preprint on this line.
