[1903.00982] Oxide: The Essence of Rust

we present Oxide, a formalized programming language close to source-level Rust (but with fully-annotated types). This presentation takes a new view of lifetimes as approximate provenances of references, and our type system is able to automatically compute this information through a flow-sensitive substructural typing judgment for which we prove syntactic type safety using progress and preservation. The result is a simpler formulation of borrow checking – including recent features such as non-lexical lifetimes – that we hope researchers will be able to use as the basis for work on Rust.