@Torre 

Thanks, however at least with Maple 14, FrameDATA help says that one

can only define an anholonomic frame relative to a previously defined

coordinate system ("To work in DifferentialGeometry with anholomonic

frames on a manifold M, first define an underlying coordinate system

on M and define the anholomonic frame or coframe relative to this

coordinate system."). Looking at the help's examples, this seems to

mean that I have to first find combinations of coordinate vector fields that satisfy

my particular Lie bracket structure relations, which is a nontrivial task

(my manifold is 4-dimensional). Is there a simple way for Maple to do that

for me?