%--------------------------------------------------------------------------
% File     : PUZ028-2 : TPTP v8.2.0. Bugfixed v1.2.0.
% Domain   : Puzzles
% Problem  : People at a party
% Version  : [SETHEO] axioms : Especial.
% English  : We can always choose 3 persons who are either familiar with
%            each other or not familiar with each other, from 6 persons
%            who meet at a party.

% Refs     :
% Source   : [SETHEO]
% Names    : ramsey1.lop [SETHEO]

% Status   : Satisfiable
% Rating   : 0.00 v5.0.0, 0.14 v4.1.0, 0.12 v4.0.1, 0.00 v2.4.0, 0.00 v2.2.1, 0.33 v2.2.0, 0.67 v2.1.0, 0.00 v2.0.0
% Syntax   : Number of clauses     :   39 (  36 unt;   1 nHn;  39 RR)
%            Number of literals    :   47 (   0 equ;   9 neg)
%            Maximal clause size   :    5 (   1 avg)
%            Maximal term depth    :    1 (   1 avg)
%            Number of predicates  :    4 (   4 usr;   0 prp; 1-2 aty)
%            Number of functors    :    6 (   6 usr;   6 con; 0-0 aty)
%            Number of variables   :    8 (   0 sgn)
% SPC      : CNF_SAT_EPR_NEQ

% Comments : This version is satisfiable because familiarity is not
%            meant in a symmetric way.
% Bugfixes : v1.2.0 - Last literal in familiar_or_not fixed.
%--------------------------------------------------------------------------
cnf(person_1,axiom,
    person(n1) ).

cnf(person_2,axiom,
    person(n2) ).

cnf(person_3,axiom,
    person(n3) ).

cnf(person_4,axiom,
    person(n4) ).

cnf(person_5,axiom,
    person(n5) ).

cnf(person_6,axiom,
    person(n6) ).

cnf(not_equal_1_2,axiom,
    not_equal(n1,n2) ).

cnf(not_equal_1_3,axiom,
    not_equal(n1,n3) ).

cnf(not_equal_1_4,axiom,
    not_equal(n1,n4) ).

cnf(not_equal_1_5,axiom,
    not_equal(n1,n5) ).

cnf(not_equal_1_6,axiom,
    not_equal(n1,n6) ).

cnf(not_equal_2_1,axiom,
    not_equal(n2,n1) ).

cnf(not_equal_2_3,axiom,
    not_equal(n2,n3) ).

cnf(not_equal_2_4,axiom,
    not_equal(n2,n4) ).

cnf(not_equal_2_5,axiom,
    not_equal(n2,n5) ).

cnf(not_equal_2_6,axiom,
    not_equal(n2,n6) ).

cnf(not_equal_3_1,axiom,
    not_equal(n3,n1) ).

cnf(not_equal_3_2,axiom,
    not_equal(n3,n2) ).

cnf(not_equal_3_4,axiom,
    not_equal(n3,n4) ).

cnf(not_equal_3_5,axiom,
    not_equal(n3,n5) ).

cnf(not_equal_3_6,axiom,
    not_equal(n3,n6) ).

cnf(not_equal_4_1,axiom,
    not_equal(n4,n1) ).

cnf(not_equal_4_2,axiom,
    not_equal(n4,n2) ).

cnf(not_equal_4_3,axiom,
    not_equal(n4,n3) ).

cnf(not_equal_4_5,axiom,
    not_equal(n4,n5) ).

cnf(not_equal_4_6,axiom,
    not_equal(n4,n6) ).

cnf(not_equal_5_1,axiom,
    not_equal(n5,n1) ).

cnf(not_equal_5_2,axiom,
    not_equal(n5,n2) ).

cnf(not_equal_5_3,axiom,
    not_equal(n5,n3) ).

cnf(not_equal_5_4,axiom,
    not_equal(n5,n4) ).

cnf(not_equal_5_6,axiom,
    not_equal(n5,n6) ).

cnf(not_equal_6_1,axiom,
    not_equal(n6,n1) ).

cnf(not_equal_6_2,axiom,
    not_equal(n6,n2) ).

cnf(not_equal_6_3,axiom,
    not_equal(n6,n3) ).

cnf(not_equal_6_4,axiom,
    not_equal(n6,n4) ).

cnf(not_equal_6_5,axiom,
    not_equal(n6,n5) ).

cnf(familiar_or_not,axiom,
    ( familiar(X,Y)
    | not_familiar(X,Y)
    | ~ person(X)
    | ~ person(Y)
    | ~ not_equal(X,Y) ) ).

cnf(three_familiar,negated_conjecture,
    ( ~ familiar(X1,X2)
    | ~ familiar(X2,X3)
    | ~ familiar(X3,X1) ) ).

cnf(three_not_familiar,negated_conjecture,
    ( ~ not_familiar(X1,X2)
    | ~ not_familiar(X2,X3)
    | ~ not_familiar(X3,X1) ) ).

%--------------------------------------------------------------------------