We investigate combinatorics of the instanton partition function for the
generic four dimensional toric orbifolds. It is shown that the orbifold
projection can be implemented by taking the inhomogeneous root of unity limit
of the q-deformed partition function. The asymptotics of the combinatorial
partition function yields the multi-matrix model for a generic β.Comment: 16 pages, 2 figures; typos corrected, references adde