Solution: Kalotan males and females

The code...


proc {Impl X Y} {FD.impl X Y 1} end   %% only simple implications

`~`=FD.nega                           % ~ is syntax for negation

proc {Kibi Sol}
   K    % Kibi's sex: 0 male, 1 female
   P1   % sex of 1st parent
   P2   % sex of 2nd parent
   KC   % Kibi's claim: 0 for "I am a boy", 1 for "I am a girl"
   TK   % truth of Kibi's claim
   T1   % truth of 1st statement
   T2   % truth of 2nd statement
   T3 ] % truth of 3rd statement
   Sol = [K P1 P2 KC TK T1 T2 T3]
   Sol ::: 0#1
   {Impl ~K TK} % if Kibi is male then his statement is true
   {FD.equi KC K} = TK % Kibi tells the truth iff his claim tells his sex   
   T1 = ~KC            % the 1st statement describes Kibi's claim
   K = T2              % the 2nd statement describes Kibi's sex
   T3 = ~TK            % the 3rd statement describes the truth of Kibi's claim
   P1 = NP2            % P1 and P2 have opposite sexes
   {Impl ~P1 T1}       % if P1 is male then T1
   {Impl NP2 T2}       % if P2 is male then T2
   {Impl NP2 T3}       % if P2 is male then T3
   {Impl P2 {FD.exor T2 T3}} % if P2 is female then either T2 or T3
   {FD.distribute naive Sol}

{ExploreAll Kibi}

Output: (1|1|0|0|0|1|1|1|nil)|nil
Thus Kibi is a girl, the first parent is her mother and the second her father, and she claimed to be a boy.

The search tree has only two choice points and two failure nodes.

Markus Löckelt