The type-settheory package

[Tags: bsd3, library]

Type classes can express sets and functions on the type level, but they are not first-class. This package expresses type-level sets and functions as types instead.

Instances are replaced by value-level proofs which can be directly manipulated; this makes quite a bit of (constructive) set theory expressible; for example, we have:

The proposition-types (derived from the :=: equality type) aren't meaningful purely by convention; they relate to the rest of Haskell as follows: A proof of A :=: B gives us a safe coercion operator A -> B (while the logic is inevitably inconsistent at compile-time since undefined proves anything, I think that we still have the property that if the Refl value is successfully pattern-matched, then the two parameters in its type are actually equal).


Versions0.1, 0.1.1, 0.1.2, 0.1.3,
Change logNone available
Dependenciesbase (==4.*), containers, mtl, syb, template-haskell, type-equality [details]
AuthorDaniel Schüssler
CategoryMath, Language
Source repositoryhead: darcs get
UploadedWed Sep 1 02:37:05 UTC 2010 by DanielSchuessler
Downloads802 total (18 in last 30 days)
0 []
StatusDocs uploaded by user
Build status unknown [no reports yet]




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