%------------------------------------------------------------------------------
% File     : SPASS---3.9
% Problem  : PUZ020-1 : TPTP v8.1.0. Released v1.0.0.
% Transfm  : none
% Format   : tptp
% Command  : run_spass %d %s

% Computer : n027.cluster.edu
% Model    : x86_64 x86_64
% CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 2.10GHz
% Memory   : 8042.1875MB
% OS       : Linux 3.10.0-693.el7.x86_64
% CPULimit : 300s
% WCLimit  : 600s
% DateTime : Mon Jul 18 18:27:18 EDT 2022

% Result   : Unsatisfiable 0.19s 0.41s
% Output   : Refutation 0.19s
% Verified : 
% SZS Type : Refutation
%            Derivation depth      :    2
%            Number of leaves      :    5
% Syntax   : Number of clauses     :    8 (   4 unt;   1 nHn;   8 RR)
%            Number of literals    :   13 (   0 equ;   6 neg)
%            Maximal clause size   :    3 (   1 avg)
%            Maximal term depth    :    2 (   1 avg)
%            Number of predicates  :    4 (   3 usr;   1 prp; 0-1 aty)
%            Number of functors    :    4 (   4 usr;   3 con; 0-1 aty)
%            Number of variables   :    0 (   0 sgn)

% Comments : 
%------------------------------------------------------------------------------
cnf(7,axiom,
    ( ~ person(u)
    | ~ a_truth(statement_by(u))
    | knight(u) ),
    file('PUZ020-1.p',unknown),
    [] ).

cnf(11,axiom,
    person(husband),
    file('PUZ020-1.p',unknown),
    [] ).

cnf(17,axiom,
    ( a_truth(statement_by(husband))
    | knight(wife) ),
    file('PUZ020-1.p',unknown),
    [] ).

cnf(18,axiom,
    ( ~ knight(wife)
    | a_truth(statement_by(husband)) ),
    file('PUZ020-1.p',unknown),
    [] ).

cnf(19,axiom,
    ~ knight(husband),
    file('PUZ020-1.p',unknown),
    [] ).

cnf(20,plain,
    a_truth(statement_by(husband)),
    inference(mrr,[status(thm)],[18,17]),
    [iquote('0:MRR:18.0,17.1')] ).

cnf(21,plain,
    ( ~ person(husband)
    | ~ a_truth(statement_by(husband)) ),
    inference(res,[status(thm),theory(equality)],[7,19]),
    [iquote('0:Res:7.2,19.0')] ).

cnf(24,plain,
    $false,
    inference(mrr,[status(thm)],[21,11,20]),
    [iquote('0:MRR:21.0,21.1,11.0,20.0')] ).

%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.04/0.12  % Problem  : PUZ020-1 : TPTP v8.1.0. Released v1.0.0.
% 0.04/0.13  % Command  : run_spass %d %s
% 0.12/0.33  % Computer : n027.cluster.edu
% 0.12/0.33  % Model    : x86_64 x86_64
% 0.12/0.33  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.12/0.33  % Memory   : 8042.1875MB
% 0.12/0.33  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.12/0.34  % CPULimit : 300
% 0.12/0.34  % WCLimit  : 600
% 0.12/0.34  % DateTime : Sun May 29 01:34:44 EDT 2022
% 0.12/0.34  % CPUTime  : 
% 0.19/0.41  
% 0.19/0.41  SPASS V 3.9 
% 0.19/0.41  SPASS beiseite: Proof found.
% 0.19/0.41  % SZS status Theorem
% 0.19/0.41  Problem: /export/starexec/sandbox2/benchmark/theBenchmark.p 
% 0.19/0.41  SPASS derived 2 clauses, backtracked 0 clauses, performed 0 splits and kept 18 clauses.
% 0.19/0.41  SPASS allocated 75591 KBytes.
% 0.19/0.41  SPASS spent	0:00:00.06 on the problem.
% 0.19/0.41  		0:00:00.04 for the input.
% 0.19/0.41  		0:00:00.00 for the FLOTTER CNF translation.
% 0.19/0.41  		0:00:00.00 for inferences.
% 0.19/0.41  		0:00:00.00 for the backtracking.
% 0.19/0.41  		0:00:00.00 for the reduction.
% 0.19/0.41  
% 0.19/0.41  
% 0.19/0.41  Here is a proof with depth 1, length 8 :
% 0.19/0.41  % SZS output start Refutation
% See solution above
% 0.19/0.41  Formulae used in the proof : knights_make_true_statements husband knight_wife_or_truthful_husband knight_wife_means_truthful_husband prove_knight_husband
% 0.19/0.41  
%------------------------------------------------------------------------------