[m-users.] How to specify the mode of a higher order predicate

[Dirk Ziegemeyer]

> Am 11.07.2015 um 02:12 schrieb Mark Brown <mark at mercurylang.org>:
> 
> On Sat, Jul 11, 2015 at 7:56 AM, Dirk Ziegemeyer <dirk at ziegemeyer.de> wrote:
>> I could not find the valid syntax yet for telling mercury the mode of list.append without wrapping it into a new predicate.
>> 
>> Is this possible?
> 
> If you use a write is as a pred expression then that will supply the info:
> 
>    Append = (pred(X::in, Y::in, Z::out) is det :- append(X, Y, Z),
>    aggregate(test2(ID), Append, [], List)

Thank you for your help on the right syntax.

Cheers,

Dirk