ON THE QUESTION OF FRIEDMAN,H

In this paper we answer a question of Friedman, providing an omega-sep arable model M of the lambda beta eta-calculus. There therefore exists an alpha-separable model for any alpha greater than or equal to 0. Th e model M permits no non-trivial enrichment as a partial order; neithe r does it permit an enrichment as a category with an initial object. T he open term model embeds in M: by way of contrast we provide a model which cannot embed in any non trivial model separating all pairs of di stinct elements. (C) 1996 Academic Press, Inc.