typeeg

Typeeg is a term used in theoretical discussions of type systems and exemplars to describe a framework that combines typed fragments with sample derivations. It serves as a lightweight notation for illustrating how a fragment can produce a given type under a particular set of typing rules.

In programming language contexts, a typeeg pair consists of a code fragment annotated with a type and an accompanying derivation that shows how the fragment satisfies the type rules. This can aid teaching, debugging, and research into type inference, coercions, and error messages, and it can support type-directed program synthesis experiments.

In linguistics and formal semantics, a closely related idea is used to annotate sentences or phrases with categorical or semantic types (such as NP, VP, or truth-condition types). A typeeg annotation helps visualize how a sequence of constituents composes to yield a target type, clarifying the role of each component in the derivation.

Typeeg notation is not yet standardized, and its specifics vary between communities. Common elements include a fragment F, a type T, and a derivation D, sometimes presented in a compact form like F : T with D below or beside it. Critics note that lack of standardization can hinder interchange and tooling, while proponents view it as a flexible pedagogical aid and research artifact.

See also: type system, typed lambda calculus, generative grammar, exemplar-based learning.