Re: Siblings of parents
Feliks Kluzniak <[email protected]>
| Newsgroups | gmane.comp.ai.prolog.swi |
|---|---|
| Message-ID | <[email protected]> |
Well, read the error message. The clauses for is_mother/2 and is_father/2 should end with periods (dots), not commas. — F. On Mar 8, 2014, at 18:21, Roelof Wobben <[email protected]> wrote: > Thanks, > > > I changed it to this: > > > male(roelof). > > male(mans). > > male(jan). > > > female(chantal). > > female(tamara). > > female(marie). > > > parent(roelof,tamara). > > parent(mans, roelof). > > parent(jan, chantal). > > parent(marie, roelof). > > parent(chantal, tamara). > > > is_mother(Child,Mother):- > > parent(Mother, Child), > > female(Mother), > > > > is_father(Child, Father):- > > parent(Father, Child), > > male(Father), > > > > > > siblings(Father,Mother) :- > > is_father(X, Father), > > is_mother(X, mother). > > > So father and mother has siblings if father is the father of X and mother is the mother of X. > > > But still errors like this: User throw: error(system_error, [type = exec, rc = 427, message = `Syntax error: Probable missplaced period around: (is_mother(H223, H224) :- parent(H224, H223) , female(H224) , is_father(H223, H240)) :- parent(H240, H223) , male(H240) , siblings(H240, H224)`, predicate = `err$exec/4`, callstack = `- catch/3;+ catch/3;- consult/1;--- top of stack ---`]) > > > Roelof > > ---------------------------------------- >> Subject: Re: [SWIPL] Siblings of parents >> From: [email protected] >> Date: Sat, 8 Mar 2014 17:35:22 +0100 >> To: [email protected] >> >> >> On 8 Mar 2014, at 17:29 , Roelof Wobben <[email protected]> wrote: >> >>> siblings(F,M) :- >>> >>> father(X) >>> >>> mother(X). >>> >>> >>> >>> So I thougth to display if parents have siblings X have to have a father and a mother. >> >> Check the meaning of these clauses. Do they express what you want to express? >> >> Another suggestion: Have a look at http://www.learnprolognow.org to get the basics of Prolog. >> >> --- nef >> > _______________________________________________ > SWI-Prolog mailing list > [email protected] > https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog