Re: where do I think wrong

> Date: Thu, 13 Mar 2014 10:19:43 +0100
> From: [email protected]
> To: [email protected]
> Subject: Re: [SWIPL] where do I think wrong
> 
> 
> Am 13.03.2014 09:04, schrieb Roelof Wobben:
> > It worked fine if a mother and father are known.
> > So I want to change it to this :
> > 
> > have_siblings(C) :-
> >     is_father(X,C),
> >     is_father(X,S); 
> >     is_mother(Y,S), 
> >     is_mother(Y,C), 
> >     C \= S,
> >     write(S).
> 
> I did not try your predicates, but there are (obviously?) parantheses
> missing. Better:
> 
> have_siblings(C) :-
>     ( ( is_father(X,C), is_father(X,S) )
>     ; ( is_mother(Y,S), is_mother(Y,C) ),
>     C \= S,
>     write(S).
> 

I changed it to what you said.

have_siblings(C) :-
    ( ( is_father(X,C), is_father(X,S) ) 
    ;( is_mother(Y,S), is_mother(Y,C) ), 
    C \= S,
    write(S).

but now I see a operand missing errror.

Roelof

 		 	   		  
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