Termination in impure lambda-calculus

We present a method for ensuring termination of lambda- calculi with references. This method makes it possible to combine measure- based techniques for termination of imperative languages with traditional approaches to termination in purely functional languages, such as logical relations. More precisely, the method lifts any termination proof for the purely functional simply-typed lambda-calculus to a termination proof for the lambda-calculus with references. The method can be made para- metric on the termination technique employed for the functional core.