We extend the first-order meta-language of Staton et al. with a new language construct, ` slice-let`. This new construct allows a user to define a random variable *x*, with a potentially intractable distribution, by introducing an auxiliary random variable, *u*, and specifying only the conditional distributions of *x* given *u* and of *u* given *x*. In effect, the distribution of x need only be defined up to some level of approximation, determined by the value of *u*. In the extended abstract, we outline the denotational semantics for `slice-let` and give some example programs. Finally, we briefly discuss an approximate representation of the program that can be used by an inference algorithm.

Authors: Ekansh Sharma and Daniel M. Roy