We present a way to combine coercive sub-typing relations, used to model ontological inclusions, and entailment using polymorphic terms provided by the lexicon in order to provide a coherent calculus integrated in L TY n. The resulting system is able to parse different types of lexical phenomena. We also illustrate differences of assumptions between related theories of lexical meaning , using the different ways to define coercive sub-typing and type systems as examples.