Summary: Higher-Order Subtyping, Revisited
Syntactic Completeness Proofs for Algorithmic Judgements
TYPES Workshop, April 21, 2006
1. Subtyping for type constructors (F
2. Proof Technique for Metatheory
∑ Elementary (no model)
∑ Works for weak theories: STL, LF
1 Higher-Order Subtyping
Subtyping for Collections
∑ When a Float is expected, an Int is acceptable.
∑ Read-only collections: a list of Ints passes for a list of Floats.
List Int List Float
∑ Mutable collections: cannot store a Float into an Int cell.