Flexible interpretation. An attractive alternative to this rigid view of the syntax-semantics interface, is the flexible interpretation of Hendriks 1993.  In this approach, a type of the syntactic source calculus is associated with an infinite set of LP types: one of these is the default semantic type associated with the syntactic source type, the others are derived from this default by means of type shifting laws. Similarly, a source calculus term is translated into an infinite set of target semantic terms; one of these is the basic translation (not necessarily of the default semantic type for the relevant syntactic category), the others are derived by the Curry-Howard term image of the typing shifting laws. The type shifting principles used are (i) argument lowering, (ii) value raising, and (iii) argument raising. The first two correspond to valid type transitions of NL; argument raising is the crucial principle that goes beyond the expressivity of the syntactic source calculi, as we saw in §2.2.