  Presented is an integral formula for solutions to the quantum
Knizhnik--Zamolodchikov equation of level $0$ associated with the vector
representation of $U_q (\widehat{ sl_n})$. This formula gives a generalization
of both our previous work for $U_q (\widehat{ sl_2})$ and Smirnov's formula for
form factors of $SU(n)$ chiral Gross-Neveu model.
