Well-defined NRC queries can be typed

Abstract

We study the expressive power of the static type system of the Nested Relational Calculus TeX and show that on so-called homogeneous input and output types, the TeX type system is expressively complete: every untyped but homogeneously well-defined TeX expression can be equivalently expressed by a well-typed expression. The TeX static type system hence does not limit the expressive power of the query writer.