A note on the proof of a theorem of Katz

Let f"[email protected]?F"q[X"1,...,X"n] be polynomials of degree d"i, 1==...>=d"r>=1. Denote the set of zeros of f"i in F"q^n by Z(f"i). Katz proved that q^@?^n^-^d^"^1^-^...^-^d^"^r^d^"^1^@? divides |Z(f"1)@[email protected]?Z(f"r)|. A more elementary proof of this result was given by Wan. We found a new and much simpler proof of this result.