There is another passage I would appreciate references on. Bell
describes the work of Poincar\e on functions invariant under groups of
linear transformations:
"...,Poincar\e solved the general algebraic equation of nth degree by
showing how its n roots can be expressed explicitly in terms of some of
the functions ha had created"
What kind of functions does he refer to and are there any good
references to this work ?
Thanks in advance
Inge H. A. Pettersen