The
symbol has symmetry properties with respect to permutation of
columns, permutation of rows, and transposition of rows and columns; these
relate 72 independent
symbols. Even (cyclic) permutations of either
columns or rows, as well as transpositions, leave the
symbol unchanged.
Odd permutations of columns or rows introduce a phase factor
, where
is the sum of all arguments of the
symbol.
For recursion relations see Varshalovich et al. (1988, §10.5).
For generating functions for the
symbol see
Biedenharn and van Dam (1965, p. 258, eq. (4.37)).
This equation is the sum rule. It constitutes an addition theorem for
the
symbol.