[Agda] Postulated computing quotients are unsound

Benja Fallenstein benja.fallenstein at gmail.com
Wed May 16 17:02:59 CEST 2012

Hi Dominique!

On Wed, May 16, 2012 at 4:27 PM, Dominique Devriese
<dominique.devriese at gmail.com> wrote:
>> * The exported constructors compute to the real ones, also in
>>  equalities. For instance, [ true ] ≡ [ false ] computes to box true ≡
>>  box false.
> Out of interest: what would happen if [_] were made abstract?

Then, alas, (elim f proof [ x ]) no longer reduces to (f x), which is
the whole point of the present exercise (you can get non-computing
quotients by simply postulating the quotient type and eliminator)...

- Benja

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