Re: Get DCG error (on any DCG clause)

[Fergus Henderson]

On 19-Nov-2001, address@hidden <address@hidden> wrote:
> Ive just installed Gprolog under linux and I'm trying to use DCGs. but
> ...
> [user].
>       Program --> A,[a].
> 
> 
> 
> gives:
>       DCG error raised: instantiation_error.

The head of a DCG clause can't be a variable,
i.e. it can't start with a capital letter.
Try

        program --> a, [a].

Of course then you'll need a definition for "a",
e.g.

        a --> ...

-- 
Fergus Henderson <address@hidden>  |  "I have always known that the pursuit
The University of Melbourne         |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.