“…The partition polynomial studied by Wagner reduces to a σ‐polynomial and the σ‐polynomial of the complement of a triangle free graph is equal to the matching generating polynomial under a simple transformation . Moreover, the widely studied adjoint polynomial (see, for example, [, , , , , , ]) is equal to the σ‐polynomial of the complement of the graph. The authors in investigate the rook and chromatic polynomials, and prove that every rook vector is a chromatic vector.…”