Before revision:  I give a set of relaxed assumptions \tilde{A} that can never be rejected and always preserve the identified set of local average treatment effect (LATE ). The LATE  is point identified and easy to estimate under \tilde{A} 
After revision:  I give a set of relaxed assumptions \tilde{A} that can never be rejected and always preserve the identified set of LATE is point identified and easy to estimate under \tilde{A}