assert semantic change proposal

[Kagamin via Digitalmars-d]

On Tuesday, 12 August 2014 at 09:17:54 UTC, Ola Fosheim Grøstad 
wrote:
> On Tuesday, 12 August 2014 at 08:07:01 UTC, Kagamin wrote:
>> A true reversal would be when preconditions are derived from 
>> postconditions.
>
> That's how you conduct a proof…

A proof usually flows from causes to consequences, the reverse 
(induction) is ambiguous. Ordering is more fundamental: you can 
define or redefine it, but it will remain, one can't think 
outside of this formalism.

> Not at all. You can create a boolean expression for every bit 
> of output and evaluate it only using NAND gates (or NOR). Not 
> practical, but doable…

Mathematics is pretty aware of differences between algorithms, 
and proving their equivalence is non-trivial.