Let U be a polydisc in C-n. Let X subset of U x C-p be apr analytic su
bset of pure dimension n such that the projection pi : U x C-p --> U e
xhibits X as an analytic branched covering of U. We show the exactness
of the Dolbeault's complex trace(pi) A(X)(r,0) -->(partial derivative
) trace(pi) A(X)(r,1)...when the Sym(k)-discriminant of pi is normal c
rossing.