Before revision:  We first show that unconstrained \epsilon-ETR = ETR  , and then study the  \epsilon-ETR problem when the solution is constrained to lie in a given  convex set.
After revision:  We first show that when the domain of the variables is \mathbb{R \epsilon-ETR = ETR , and then study the \epsilon-ETR problem when the solution is constrained to lie in a given convex set.