F- and H-Triangles for ν-Associahedra

For any northeast path ν, we define two bivariate polynomials associated with the ν-associahedron: the F- and the H-triangle. We prove combinatorially that we can obtainone from the other by an invertible transformation of variables. These polynomials generalize the classical F- and H-triangles of F. Chapoton in type A. Our proof is completely newand has the advantage of providing a combinatorial explanation of the relation between the F- and H-triangle.