ABSTRACT. Let (R, M) be a local ring with infinite residue field and / = (xi,... ,Xd)R an ideal generated by a system of parameters. It is shown that the multiplicity of / equals the multiplicity of IT where and R = R/(0: x%),N\axge.
Introduction.Let (R, M) be a local ring with infinite residue field. A device commonly employed in studying the multiplicity of an M-primary ideal is to go mod a superficial element. The effect is to reduce the dimension of the ring yet preserve the multiplicity. This technique is particularly useful in proving theorems about multiplicity by induction on the dimension of R. There are however, occasions when this process can be ineffective-certain properties do not lift from homomorphic images. Here we show that this difficulty can sometimes be circumvented by preserving the multiplicity upon passing to subrings of the total quotient ring of R having smaller dimension. To wit, we prove that if / = (xi,..., x<¡)R is an ideal generated by a system of parameters, then the multiplicity of / is the same