[Agda] Automatic conversion between records and iterated Sigma types

Martin Escardo m.escardo at cs.bham.ac.uk
Mon Apr 13 21:34:38 CEST 2020


Because records are more convenient notationally, but Sigma types are 
more convenient mathematically, as they allow a uniform treatment. You 
can prove loads of preservation properties for Sigma formation, and if 
you use records you have to repeat these proofs. A record *is* the same 
thing as an iterated Sigma type, and this needs to be made official from 
a mathematical point of view. This is particularly important in 
univalent mathematics. The only reason I don't use record types in my 
developments is this. I would rather use records, but then I would need 
to reprove everything again, or transport it along equivalences (and 
none of these two options is attractive). Martin

On 13/04/2020 20:25, Thorsten Altenkirch wrote:
> Why would anybody do something like this?
> 
> Sent from my iPhone
> 
>> On 13 Apr 2020, at 19:48, Martin Escardo <m.escardo at cs.bham.ac.uk> wrote:
>>
>> Is it possible to write a tactic to convert between records and equivalent iterated Sigma types? And, if so, to also produce code to establish their equivalence?
>>
>> Thanks,
>> Martin
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-- 
Martin Escardo
http://www.cs.bham.ac.uk/~mhe


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