Martin Sulzmann wrote:
Mark P Jones wrote:
In fact, the two sets of dependencies that you have given here are provably equivalent, so it would be decidedly odd to have a "type improvement" system that distinguishes between them.
Based on the FD-CHR formulation, for the single-range FD case we get [...] which is clearly weaker. [...] So, I conclude that in the Haskell type improvement context there's clearly a difference among single-range and multi-range FDs.
This seems like a flaw in FD-CHR, rather than a fundamental difference between the dependencies.
Of course, we could define multi-range FDs in terms of single-range FDs which then trivially solves the "equivalence" problem (but some user may be disappointed that their multi-range FDs yield weaker improvement).
Why not instead transform single-range FDs into multi-range ones where possible? Ganesh ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================