The exact combination of internal and of geometrical symmetries in curved space‐times is
discussed. It is seen that it is possible to define locally a Lie group S containing two
noninvariant subgroups E and G, such that in the flat limit of the space‐time, S decomposes
in the product of the Poincaré group resulting from a contraction of E and an internal group
with point dependent parameters resulting fom G. Furthermore, E does not have necessarily
a nilpotent action on S except in the flat limit. An explicit squared mass‐splitting expression …