[Agda] syntax declaration

[Michel Levy]

Alas, the suggestion of Martin "syntax exists A P   = ex  x : A , P x"
doesn't work.

I  still have the error : syntax must alternate holes and non-holes.

And I get a lexical error when I replace the colon : by \:4

I  read
"https://agda.readthedocs.io/en/v2.6.0/language/syntax-declarations.html"
without finding the solution.

Remark : I'm using agda version 2.5.3

Le 23/03/2020 à 18:19, Martin Escardo a écrit :
> Also you will need to write
>
> syntax exists A P   = ex  x : A , P x
>
> without the round brackets, I think.
>
> Martin
>
>
> On 23/03/2020 17:18, Martin Escardo wrote:
>> Use a different colon (:) symbol, such as the one you get by typing
>> \:4 in emacs. I think the normal colon is reserved. Martin
>>
>> On 23/03/2020 16:53, michel.levy.imag at free.fr wrote:
>>> I made the following statement
>>>
>>> data exists (A : Set)(P : A -> Set): Set where
>>>    <_,_> : (a : A) -> P a -> exists A P
>>>
>>> I would like to rewrite (exists A P) as, for example,  (ex (x : A) P
>>> x).
>>> But I don't understand how to do it. I tried :
>>>
>>> syntax exists A P   = ex  (x : A) , P x
>>>
>>> but I had the mistake : syntax must use holes exactly once
>>>
>>> Can you explain to me how to use the syntax declaration on this
>>> example ? What are these holes in my syntax statement ?
>>>
>>
>
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