O'Haskell is a programming language derived from Haskell by the addition of concurrent reactive objects and subtyping. Because Haskell already encompasses an advanced type sy...
We extend classical first-order logic with subtyping by type predicates and type coercion. Type predicates assert that the value of a term belongs to a more special type than the ...
The inclusion of Regular Expressions (REs) is the kernel of any type-checking algorithm for XML manipulation languages. XML applications would benefit from the extension of REs wi...
We show how to implement a calculus with higher-order subtyping and subkinding by replacing uses of implicit subsumption with explicit coercions. To ensure this can be done, a pol...
We present a statically typed, class-based object oriented language where classes are first class polymorphic values. A main contribution of this work is the design of a type syst...