Internship report: Uniform and non-structural subtyping
نویسندگان
چکیده
We expose a new approach to tackle non-structural subtyping problems. We introduce uniform subtyping as a means to capture some properties of non-structural subtyping. In the uniform theory, we show that the validity of a first-order sentence is decidable, and entailment is PSPACEhard. In addition, we give decidable approximations to entailment and subtyping constrained types — two problems which are still open in the non-structural theory.
منابع مشابه
On the Theory of Structural Subtyping
We show that the first-order theory of structural subtyping of non-recursive types is decidable. Let Σ be a language consisting of function symbols (representing type constructors) and C a decidable structure in the relational language L containing a binary relation ≤. C represents primitive types; ≤ represents a subtype ordering. We introduce the notion of Σ-term-power of C, which generalizes ...
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