Value Range Propigation Spec

[Timon Gehr via Digitalmars-d]

On 10/22/2014 10:32 PM, Walter Bright wrote:
> The specification is straightforward - a narrowing conversion can be
> implicitly performed if it can be proved that it would not lose
> information.

This is only straightforward to state because it is so ill-defined.
The main aspect in need of specification is the procedure to perform 
those automated proofs with.