How to express constraint succeeded?

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How to express constraint succeeded?

Paul
Hello, Dear Cafe! I have expression

     'True ~ 'True

in right hand side of type level function. Is some "constant" for the same?

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Re: How to express constraint succeeded?

Li-yao Xia-2
Hello Paul,

     (() :: Constraint)

is the empty constraint. The kind annotation is sometimes optional but
useful to disambiguate from the unit type.

Li-yao

On 08/23/2018 07:18 AM, Paul wrote:

> Hello, Dear Cafe! I have expression
>
>      'True ~ 'True
>
> in right hand side of type level function. Is some "constant" for the same?
>
> _______________________________________________
> Haskell-Cafe mailing list
> To (un)subscribe, modify options or view archives go to:
> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
> Only members subscribed via the mailman list are allowed to post.
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Re: How to express constraint succeeded?

Paul
Ooh, yes! Thank you very much!


23.08.2018 14:24, Li-yao Xia wrote:

> Hello Paul,
>
>     (() :: Constraint)
>
> is the empty constraint. The kind annotation is sometimes optional but
> useful to disambiguate from the unit type.
>
> Li-yao
>
> On 08/23/2018 07:18 AM, Paul wrote:
>> Hello, Dear Cafe! I have expression
>>
>>      'True ~ 'True
>>
>> in right hand side of type level function. Is some "constant" for the
>> same?
>>
>> _______________________________________________
>> Haskell-Cafe mailing list
>> To (un)subscribe, modify options or view archives go to:
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
>> Only members subscribed via the mailman list are allowed to post.
> _______________________________________________
> Haskell-Cafe mailing list
> To (un)subscribe, modify options or view archives go to:
> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
> Only members subscribed via the mailman list are allowed to post.

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