From: keith on
Bernard Parisse's Erable 3.2 manual mentions (p.49) that:

"There is currently only one program available in the other directory,
written in
UserRPL by John Wilson, that I have translated into SysRPL, it is
named TNBA
for tangent, normal, binormal, acceleration. It takes a 3-dimensional
vector (as
a list) at level 1 (e.g. { '2*T' 1 'T^2' }) and returns the position,
normal and binormal vectors as well as the tangential and normal

I checked and google searched but have found no listing of
John Wilson's original Differential Geometry UserRPL program. Does
anyone know where it might be available?