# [Agda] Recursive Sets / refine vs. load

Altenkirch Thorsten psztxa at exmail.nottingham.ac.uk
Wed Mar 28 13:52:05 CEST 2012

Could you make this more precise, Andreas?

It seems that the approach using equations also exploits that we define
everything top-level.
I don't see how to generalize this in a way which would extend uniformly
to eliminators appearing
anywhere. But maybe this is just my limitation...

Cheers,
Thorsten

On 27/03/2012 21:07, "Andreas Abel" <andreas.abel at ifi.lmu.de> wrote:

> Well, you could make sense of this, even if thinking it as a case.
> But then, the boundary between type-checked code that can be evaluated
> and not-yet-type-checked code is within terms, not only declarations.
>
> Cheers,
> Andreas
>
> On Sun, 25 Mar 2012 16:55:36 +0100, Altenkirch Thorsten wrote:
>> To me pattern matching is just a shorthand for using eliminators such
>> as case. In this view it is hard to make sense of your suggestion.
>>
>> Cheers,
>> Thorsten
>>
>>
>> On 24 Mar 2012, at 22:13, "Nils Anders Danielsson" <nad at chalmers.se>
>> wrote:
>>
>>> On 2012-03-24 18:12, Brandon Moore wrote:
>>>> The following definition looks reasonable to me,
>>>> the type of the hole is reported as ℕ → Set,
>>>> and refine/give accepts what I've written there,
>>>> but then typechecking the file fails, saying
>>>> t true !=< ℕ of type Set
>>>
>>> [...]
>>>
>>>> t : Bool → Set
>>>> t true = ℕ
>>>> t false = Σ (t true) {!Vec Bool!}
>>>>
>>>> Why isn't this definition accepted?
>>>
>>> Because (non-mutual) definitions are not unfolded before they have
>>> been
>>> type-checked. Unfortunately this does not apply to goals: Agda
>>> forgets
>>> that t should not unfold when Vec Bool is type-checked. This is a
>>> long-standing bug:
>>>
>>>
>>> --
>>>
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>--
> Andreas Abel  <><     Du bist der geliebte Mensch.
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> Theoretical Computer Science, University of Munich
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