Division of Mathematical Sciences, Pukyong National University, Busan 608-737, South Korea
Copyright © 2010 Jin-Mun Jeong et al. This is an open access article distributed under the
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We deal with the approximate controllability for the nonlinear functional differential equation governed by the variational inequality in Hilbert spaces and present a general theorems under which previous results easily follow. The common research direction is to find conditions on the nonlinear term such that controllability is preserved under perturbation.