Introducing Nullable Reference Types in C#. Is there hope for D, too?

[Ola Fosheim Grostad]

On Thursday, 23 November 2017 at 01:33:39 UTC, codephantom wrote:
> On Thursday, 23 November 2017 at 00:15:56 UTC, Ola Fosheim 
> Grostad wrote:
>> By what proof? And what do you mean by mathematics?
>
> A mathematical claim, that cannot be proven or disproven, is 
> neither true or false.
>
> What you are left with, is just a possibility.

And how is this a problem? If your program relies upon the 
unbounded version you will have to introduce it explicitky as an 
axiom. But you dont have to, you can use bounded quantifiers.

What you seem to be saying is that one should accept all unproven 
statements as axioms implicitly. Why have a type system at all 
then?

> Thus, it will always remain an open question as to whether the 
> conjecture is true, or not.

Heh, has the Goldbach conjecture been proven undecidable?