The isomorphism SU(4)\simeq O(6) is used to construct the form factors of the
O(6) Gross–Neveu model as bound state form factors of the SU(4) chiral
Gross–Neveu model. This technique is generalized and is then applied to use
the O(6) as the starting point of the nesting procedure to obtain the O(N)
form factors for general even N
