TSTP Solution File: GRP775+1 by Otter---3.3

View Problem - Process Solution

%------------------------------------------------------------------------------
% File     : Otter---3.3
% Problem  : GRP775+1 : TPTP v8.1.0. Released v4.1.0.
% Transfm  : none
% Format   : tptp:raw
% Command  : otter-tptp-script %s

% Computer : n015.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  : 300s
% DateTime : Wed Jul 27 12:57:48 EDT 2022

% Result   : Theorem 27.73s 27.87s
% Output   : Refutation 27.73s
% Verified : 
% SZS Type : Refutation
%            Derivation depth      :   15
%            Number of leaves      :   15
% Syntax   : Number of clauses     :   72 (  36 unt;   4 nHn;  52 RR)
%            Number of literals    :  119 (  48 equ;  47 neg)
%            Maximal clause size   :    4 (   1 avg)
%            Maximal term depth    :    5 (   1 avg)
%            Number of predicates  :    5 (   3 usr;   1 prp; 0-2 aty)
%            Number of functors    :    4 (   4 usr;   2 con; 0-2 aty)
%            Number of variables   :   95 (   0 sgn)

% Comments : 
%------------------------------------------------------------------------------
cnf(1,axiom,
    ( ~ l(A,B)
    | product(A,B) = A ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(2,axiom,
    ( ~ l(A,B)
    | product(B,A) = B ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(3,axiom,
    ( l(A,B)
    | product(A,B) != A
    | product(B,A) != B ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(4,axiom,
    ( ~ r(A,B)
    | product(A,B) = B ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(5,axiom,
    ( ~ r(A,B)
    | product(B,A) = A ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(6,axiom,
    ( r(A,B)
    | product(A,B) != B
    | product(B,A) != A ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(7,axiom,
    ( ~ d(A,B)
    | r(A,dollar_f1(A,B)) ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(8,axiom,
    ( ~ d(A,B)
    | l(dollar_f1(A,B),B) ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(9,axiom,
    ( d(A,B)
    | ~ r(A,C)
    | ~ l(C,B) ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(10,axiom,
    ( ~ d(dollar_c2,dollar_c1)
    | product(dollar_c2,product(dollar_c1,dollar_c2)) != dollar_c2
    | product(dollar_c1,product(dollar_c2,dollar_c1)) != dollar_c1 ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(11,plain,
    ( l(A,A)
    | product(A,A) != A ),
    inference(factor,[status(thm)],[3]),
    [iquote('factor,3.2.3')] ).

cnf(12,plain,
    ( r(A,A)
    | product(A,A) != A ),
    inference(factor,[status(thm)],[6]),
    [iquote('factor,6.2.3')] ).

cnf(13,axiom,
    A = A,
    file('GRP775+1.p',unknown),
    [] ).

cnf(15,axiom,
    product(product(A,B),C) = product(A,product(B,C)),
    file('GRP775+1.p',unknown),
    [] ).

cnf(17,axiom,
    product(A,A) = A,
    file('GRP775+1.p',unknown),
    [] ).

cnf(18,axiom,
    ( d(dollar_c2,dollar_c1)
    | product(dollar_c2,product(dollar_c1,dollar_c2)) = dollar_c2 ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(19,axiom,
    ( d(dollar_c2,dollar_c1)
    | product(dollar_c1,product(dollar_c2,dollar_c1)) = dollar_c1 ),
    file('GRP775+1.p',unknown),
    [] ).

cnf(20,plain,
    r(A,A),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(back_demod,[status(thm)],[12]),17]),13]),
    [iquote('back_demod,12,demod,17,unit_del,13')] ).

cnf(21,plain,
    l(A,A),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(back_demod,[status(thm)],[11]),17]),13]),
    [iquote('back_demod,11,demod,17,unit_del,13')] ).

cnf(26,plain,
    product(A,product(A,B)) = product(A,B),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[15,17])]),
    [iquote('para_into,14.1.1.1,16.1.1,flip.1')] ).

cnf(27,plain,
    ( product(A,product(B,C)) = product(B,C)
    | ~ r(B,A) ),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[15,5])]),
    [iquote('para_into,14.1.1.1,5.2.1,flip.1')] ).

cnf(29,plain,
    ( product(A,product(B,C)) = product(A,C)
    | ~ l(B,A) ),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[15,2])]),
    [iquote('para_into,14.1.1.1,2.2.1,flip.1')] ).

cnf(30,plain,
    ( product(A,product(B,C)) = product(A,C)
    | ~ l(A,B) ),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[15,1])]),
    [iquote('para_into,14.1.1.1,1.2.1,flip.1')] ).

cnf(32,plain,
    product(A,product(B,product(A,B))) = product(A,B),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[15,17])]),
    [iquote('para_into,14.1.1,16.1.1,flip.1')] ).

cnf(33,plain,
    ( product(A,product(B,C)) = C
    | ~ r(C,product(A,B)) ),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[15,5])]),
    [iquote('para_into,14.1.1,5.2.1,flip.1')] ).

cnf(34,plain,
    ( product(A,product(B,C)) = C
    | ~ r(product(A,B),C) ),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[15,4])]),
    [iquote('para_into,14.1.1,4.2.1,flip.1')] ).

cnf(37,plain,
    ( r(A,product(B,C))
    | product(A,product(B,C)) != product(B,C)
    | product(B,product(C,A)) != A ),
    inference(para_from,[status(thm),theory(equality)],[15,6]),
    [iquote('para_from,14.1.1,6.3.1')] ).

cnf(49,plain,
    product(A,product(B,product(A,product(B,C)))) = product(A,product(B,C)),
    inference(demod,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[26,15]),15,15]),
    [iquote('para_into,25.1.1.2,14.1.1,demod,15,15')] ).

cnf(52,plain,
    ( product(A,B) = A
    | ~ l(A,product(A,B)) ),
    inference(flip,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[26,1])]),
    [iquote('para_into,25.1.1,1.2.1,flip.1')] ).

cnf(53,plain,
    ( r(product(A,B),A)
    | product(A,product(B,A)) != A ),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(para_from,[status(thm),theory(equality)],[26,6]),15]),13]),
    [iquote('para_from,25.1.1,6.3.1,demod,15,unit_del,13')] ).

cnf(87,plain,
    ( l(product(dollar_c2,dollar_c1),dollar_c1)
    | d(dollar_c2,dollar_c1) ),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(para_from,[status(thm),theory(equality)],[19,3]),15,17]),13,13]),
    [iquote('para_from,19.2.1,3.3.1,demod,15,17,unit_del,13,13')] ).

cnf(252,plain,
    ( product(A,B) = product(A,C)
    | ~ l(A,B)
    | ~ l(C,B) ),
    inference(para_into,[status(thm),theory(equality)],[30,2]),
    [iquote('para_into,30.1.1.2,2.2.1')] ).

cnf(270,plain,
    ( product(A,product(B,C)) = A
    | ~ l(A,product(A,C))
    | ~ l(A,B) ),
    inference(para_from,[status(thm),theory(equality)],[30,52]),
    [iquote('para_from,30.1.1,52.2.2')] ).

cnf(383,plain,
    ( ~ d(dollar_c2,dollar_c1)
    | product(dollar_c1,product(dollar_c2,dollar_c1)) != dollar_c1
    | ~ r(dollar_c2,product(dollar_c2,dollar_c1)) ),
    inference(unit_del,[status(thm)],[inference(para_from,[status(thm),theory(equality)],[33,10]),13]),
    [iquote('para_from,33.1.1,10.2.1,unit_del,13')] ).

cnf(385,plain,
    ( l(product(A,B),C)
    | product(A,product(B,C)) != product(A,B)
    | B != C
    | ~ r(B,product(C,A)) ),
    inference(demod,[status(thm),theory(equality)],[inference(para_from,[status(thm),theory(equality)],[33,3]),15]),
    [iquote('para_from,33.1.1,3.3.1,demod,15')] ).

cnf(429,plain,
    ( product(A,B) = B
    | ~ r(product(A,B),B) ),
    inference(para_into,[status(thm),theory(equality)],[34,17]),
    [iquote('para_into,34.1.1.2,16.1.1')] ).

cnf(459,plain,
    ( product(A,product(B,C)) = C
    | ~ r(A,C)
    | ~ l(A,B) ),
    inference(para_into,[status(thm),theory(equality)],[34,1]),
    [iquote('para_into,34.2.1,1.2.1')] ).

cnf(841,plain,
    ( r(dollar_c2,product(dollar_c2,dollar_c1))
    | d(dollar_c2,dollar_c1) ),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[37,18]),26]),13,13]),
    [iquote('para_into,37.3.1,18.2.1,demod,26,unit_del,13,13')] ).

cnf(872,plain,
    d(dollar_c2,dollar_c1),
    inference(factor_simp,[status(thm)],[inference(factor_simp,[status(thm)],[inference(hyper,[status(thm)],[841,9,87])])]),
    [iquote('hyper,841,9,87,factor_simp,factor_simp')] ).

cnf(947,plain,
    l(dollar_f1(dollar_c2,dollar_c1),dollar_c1),
    inference(hyper,[status(thm)],[872,8]),
    [iquote('hyper,872,8')] ).

cnf(948,plain,
    r(dollar_c2,dollar_f1(dollar_c2,dollar_c1)),
    inference(hyper,[status(thm)],[872,7]),
    [iquote('hyper,872,7')] ).

cnf(951,plain,
    product(dollar_c1,product(dollar_f1(dollar_c2,dollar_c1),A)) = product(dollar_c1,A),
    inference(hyper,[status(thm)],[947,29]),
    [iquote('hyper,947,29')] ).

cnf(955,plain,
    product(dollar_c1,dollar_f1(dollar_c2,dollar_c1)) = dollar_c1,
    inference(hyper,[status(thm)],[947,2]),
    [iquote('hyper,947,2')] ).

cnf(957,plain,
    product(dollar_f1(dollar_c2,dollar_c1),dollar_c1) = dollar_f1(dollar_c2,dollar_c1),
    inference(hyper,[status(thm)],[947,1]),
    [iquote('hyper,947,1')] ).

cnf(966,plain,
    product(dollar_f1(dollar_c2,dollar_c1),product(dollar_c2,A)) = product(dollar_c2,A),
    inference(hyper,[status(thm)],[948,27]),
    [iquote('hyper,948,27')] ).

cnf(971,plain,
    product(dollar_c2,dollar_f1(dollar_c2,dollar_c1)) = dollar_f1(dollar_c2,dollar_c1),
    inference(hyper,[status(thm)],[948,4]),
    [iquote('hyper,948,4')] ).

cnf(1279,plain,
    r(product(A,B),product(A,product(B,A))),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[53,32]),15,15,32,15,17]),13]),
    [iquote('para_into,53.2.1.2,31.1.1,demod,15,15,32,15,17,unit_del,13')] ).

cnf(1284,plain,
    r(product(A,product(B,A)),product(A,B)),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[53,26]),15,17]),13]),
    [iquote('para_into,53.2.1.2,25.1.1,demod,15,17,unit_del,13')] ).

cnf(1664,plain,
    product(A,product(dollar_c2,product(A,dollar_f1(dollar_c2,dollar_c1)))) = product(A,dollar_f1(dollar_c2,dollar_c1)),
    inference(demod,[status(thm),theory(equality)],[inference(para_from,[status(thm),theory(equality)],[971,49]),971]),
    [iquote('para_from,970.1.1,49.1.1.2.2.2,demod,971')] ).

cnf(3417,plain,
    ( r(A,product(A,B))
    | ~ r(product(B,A),A) ),
    inference(demod,[status(thm),theory(equality)],[inference(para_from,[status(thm),theory(equality)],[429,1284]),17]),
    [iquote('para_from,429.1.1,1284.1.1.2,demod,17')] ).

cnf(3721,plain,
    ( product(dollar_c1,A) = dollar_c1
    | ~ l(dollar_f1(dollar_c2,dollar_c1),A) ),
    inference(flip,[status(thm),theory(equality)],[inference(demod,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[951,1]),955])]),
    [iquote('para_into,951.1.1.2,1.2.1,demod,955,flip.1')] ).

cnf(3759,plain,
    r(product(dollar_c2,A),product(dollar_c2,product(A,dollar_f1(dollar_c2,dollar_c1)))),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(para_from,[status(thm),theory(equality)],[966,3417]),15]),20]),
    [iquote('para_from,965.1.1,3417.2.1,demod,15,unit_del,20')] ).

cnf(3910,plain,
    ( product(A,product(B,A)) = A
    | ~ l(A,B) ),
    inference(unit_del,[status(thm)],[inference(para_into,[status(thm),theory(equality)],[270,17]),21]),
    [iquote('para_into,270.2.2,16.1.1,unit_del,21')] ).

cnf(4182,plain,
    ( l(product(A,B),B)
    | ~ r(B,product(B,A)) ),
    inference(unit_del,[status(thm)],[inference(para_into,[status(thm),theory(equality)],[385,17]),13,13]),
    [iquote('para_into,385.2.1.2,16.1.1,unit_del,13,13')] ).

cnf(4185,plain,
    l(product(A,B),product(B,product(A,B))),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[4182,32]),15,15,32]),1284]),
    [iquote('para_into,4182.1.1,31.1.1,demod,15,15,32,unit_del,1284')] ).

cnf(4196,plain,
    d(product(A,B),product(B,A)),
    inference(demod,[status(thm),theory(equality)],[inference(hyper,[status(thm)],[4185,9,1279]),15,26,32]),
    [iquote('hyper,4185,9,1279,demod,15,26,32')] ).

cnf(4211,plain,
    ( d(A,product(B,A))
    | ~ l(A,B) ),
    inference(demod,[status(thm),theory(equality)],[inference(para_into,[status(thm),theory(equality)],[4196,3910]),15,17]),
    [iquote('para_into,4196.1.1,3910.1.1,demod,15,17')] ).

cnf(4243,plain,
    ( d(A,B)
    | ~ l(A,B) ),
    inference(factor_simp,[status(thm)],[inference(para_into,[status(thm),theory(equality)],[4211,2])]),
    [iquote('para_into,4211.1.2,2.2.1,factor_simp')] ).

cnf(4457,plain,
    d(product(dollar_c2,A),product(A,dollar_f1(dollar_c2,dollar_c1))),
    inference(demod,[status(thm),theory(equality)],[inference(hyper,[status(thm)],[3759,9,4185]),15,966,1664]),
    [iquote('hyper,3759,9,4185,demod,15,966,1664')] ).

cnf(4466,plain,
    d(product(dollar_c2,dollar_c1),dollar_c1),
    inference(unit_del,[status(thm)],[inference(para_into,[status(thm),theory(equality)],[4457,3721]),21]),
    [iquote('para_into,4457.1.2,3721.1.1,unit_del,21')] ).

cnf(4469,plain,
    l(dollar_f1(product(dollar_c2,dollar_c1),dollar_c1),dollar_c1),
    inference(hyper,[status(thm)],[4466,8]),
    [iquote('hyper,4466,8')] ).

cnf(4470,plain,
    r(product(dollar_c2,dollar_c1),dollar_f1(product(dollar_c2,dollar_c1),dollar_c1)),
    inference(hyper,[status(thm)],[4466,7]),
    [iquote('hyper,4466,7')] ).

cnf(4490,plain,
    d(dollar_f1(product(dollar_c2,dollar_c1),dollar_c1),dollar_c1),
    inference(hyper,[status(thm)],[4469,4243]),
    [iquote('hyper,4469,4243')] ).

cnf(4509,plain,
    product(dollar_c1,dollar_f1(product(dollar_c2,dollar_c1),dollar_c1)) = dollar_c1,
    inference(flip,[status(thm),theory(equality)],[inference(demod,[status(thm),theory(equality)],[inference(hyper,[status(thm)],[4469,252,21]),17])]),
    [iquote('hyper,4469,252,21,demod,17,flip.1')] ).

cnf(4511,plain,
    l(dollar_f1(dollar_f1(product(dollar_c2,dollar_c1),dollar_c1),dollar_c1),dollar_c1),
    inference(hyper,[status(thm)],[4490,8]),
    [iquote('hyper,4490,8')] ).

cnf(4528,plain,
    dollar_f1(product(dollar_c2,dollar_c1),dollar_c1) = product(dollar_c2,dollar_c1),
    inference(flip,[status(thm),theory(equality)],[inference(demod,[status(thm),theory(equality)],[inference(hyper,[status(thm)],[4470,459,4185]),15,15,4509,15,26,32])]),
    [iquote('hyper,4470,459,4185,demod,15,15,4509,15,26,32,flip.1')] ).

cnf(4529,plain,
    l(product(dollar_c2,dollar_c1),dollar_c1),
    inference(demod,[status(thm),theory(equality)],[inference(back_demod,[status(thm)],[4511]),4528,4528]),
    [iquote('back_demod,4511,demod,4528,4528')] ).

cnf(4532,plain,
    product(dollar_c1,product(dollar_c2,dollar_c1)) = dollar_c1,
    inference(demod,[status(thm),theory(equality)],[inference(back_demod,[status(thm)],[4509]),4528]),
    [iquote('back_demod,4508,demod,4528')] ).

cnf(4539,plain,
    ~ r(dollar_c2,product(dollar_c2,dollar_c1)),
    inference(unit_del,[status(thm)],[inference(demod,[status(thm),theory(equality)],[inference(back_demod,[status(thm)],[383]),4532]),872,13]),
    [iquote('back_demod,383,demod,4532,unit_del,872,13')] ).

cnf(4550,plain,
    product(dollar_c2,dollar_c1) = dollar_f1(dollar_c2,dollar_c1),
    inference(flip,[status(thm),theory(equality)],[inference(demod,[status(thm),theory(equality)],[inference(hyper,[status(thm)],[4529,252,947]),957,966])]),
    [iquote('hyper,4529,252,947,demod,957,966,flip.1')] ).

cnf(4552,plain,
    ~ r(dollar_c2,dollar_f1(dollar_c2,dollar_c1)),
    inference(demod,[status(thm),theory(equality)],[inference(back_demod,[status(thm)],[4539]),4550]),
    [iquote('back_demod,4539,demod,4550')] ).

cnf(4553,plain,
    $false,
    inference(binary,[status(thm)],[4552,948]),
    [iquote('binary,4552.1,948.1')] ).

%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.06/0.11  % Problem  : GRP775+1 : TPTP v8.1.0. Released v4.1.0.
% 0.06/0.12  % Command  : otter-tptp-script %s
% 0.12/0.33  % Computer : n015.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
% 0.12/0.33  % CPULimit : 300
% 0.12/0.33  % WCLimit  : 300
% 0.12/0.33  % DateTime : Wed Jul 27 05:44:26 EDT 2022
% 0.12/0.33  % CPUTime  : 
% 27.73/27.87  ----- Otter 3.3f, August 2004 -----
% 27.73/27.87  The process was started by sandbox on n015.cluster.edu,
% 27.73/27.87  Wed Jul 27 05:44:26 2022
% 27.73/27.87  The command was "./otter".  The process ID is 20885.
% 27.73/27.87  
% 27.73/27.87  set(prolog_style_variables).
% 27.73/27.87  set(auto).
% 27.73/27.87     dependent: set(auto1).
% 27.73/27.87     dependent: set(process_input).
% 27.73/27.87     dependent: clear(print_kept).
% 27.73/27.87     dependent: clear(print_new_demod).
% 27.73/27.87     dependent: clear(print_back_demod).
% 27.73/27.87     dependent: clear(print_back_sub).
% 27.73/27.87     dependent: set(control_memory).
% 27.73/27.87     dependent: assign(max_mem, 12000).
% 27.73/27.87     dependent: assign(pick_given_ratio, 4).
% 27.73/27.87     dependent: assign(stats_level, 1).
% 27.73/27.87     dependent: assign(max_seconds, 10800).
% 27.73/27.87  clear(print_given).
% 27.73/27.87  
% 27.73/27.87  formula_list(usable).
% 27.73/27.87  all A (A=A).
% 27.73/27.87  all C B A (product(product(A,B),C)=product(A,product(B,C))).
% 27.73/27.87  all A (product(A,A)=A).
% 27.73/27.87  all X0 X1 (l(X0,X1)<->product(X0,X1)=X0&product(X1,X0)=X1).
% 27.73/27.87  all X2 X3 (r(X2,X3)<->product(X2,X3)=X3&product(X3,X2)=X2).
% 27.73/27.87  all X4 X5 (d(X4,X5)<-> (exists X6 (r(X4,X6)&l(X6,X5)))).
% 27.73/27.87  -(all X7 X8 (d(X7,X8)<->product(X7,product(X8,X7))=X7&product(X8,product(X7,X8))=X8)).
% 27.73/27.87  end_of_list.
% 27.73/27.87  
% 27.73/27.87  -------> usable clausifies to:
% 27.73/27.87  
% 27.73/27.87  list(usable).
% 27.73/27.87  0 [] A=A.
% 27.73/27.87  0 [] product(product(A,B),C)=product(A,product(B,C)).
% 27.73/27.87  0 [] product(A,A)=A.
% 27.73/27.87  0 [] -l(X0,X1)|product(X0,X1)=X0.
% 27.73/27.87  0 [] -l(X0,X1)|product(X1,X0)=X1.
% 27.73/27.87  0 [] l(X0,X1)|product(X0,X1)!=X0|product(X1,X0)!=X1.
% 27.73/27.87  0 [] -r(X2,X3)|product(X2,X3)=X3.
% 27.73/27.87  0 [] -r(X2,X3)|product(X3,X2)=X2.
% 27.73/27.87  0 [] r(X2,X3)|product(X2,X3)!=X3|product(X3,X2)!=X2.
% 27.73/27.87  0 [] -d(X4,X5)|r(X4,$f1(X4,X5)).
% 27.73/27.87  0 [] -d(X4,X5)|l($f1(X4,X5),X5).
% 27.73/27.87  0 [] d(X4,X5)| -r(X4,X6)| -l(X6,X5).
% 27.73/27.87  0 [] d($c2,$c1)|product($c2,product($c1,$c2))=$c2.
% 27.73/27.87  0 [] d($c2,$c1)|product($c1,product($c2,$c1))=$c1.
% 27.73/27.87  0 [] -d($c2,$c1)|product($c2,product($c1,$c2))!=$c2|product($c1,product($c2,$c1))!=$c1.
% 27.73/27.87  end_of_list.
% 27.73/27.87  
% 27.73/27.87  SCAN INPUT: prop=0, horn=0, equality=1, symmetry=0, max_lits=3.
% 27.73/27.87  
% 27.73/27.87  This ia a non-Horn set with equality.  The strategy will be
% 27.73/27.87  Knuth-Bendix, ordered hyper_res, factoring, and unit
% 27.73/27.87  deletion, with positive clauses in sos and nonpositive
% 27.73/27.87  clauses in usable.
% 27.73/27.87  
% 27.73/27.87     dependent: set(knuth_bendix).
% 27.73/27.87     dependent: set(anl_eq).
% 27.73/27.87     dependent: set(para_from).
% 27.73/27.87     dependent: set(para_into).
% 27.73/27.87     dependent: clear(para_from_right).
% 27.73/27.87     dependent: clear(para_into_right).
% 27.73/27.87     dependent: set(para_from_vars).
% 27.73/27.87     dependent: set(eq_units_both_ways).
% 27.73/27.87     dependent: set(dynamic_demod_all).
% 27.73/27.87     dependent: set(dynamic_demod).
% 27.73/27.87     dependent: set(order_eq).
% 27.73/27.87     dependent: set(back_demod).
% 27.73/27.87     dependent: set(lrpo).
% 27.73/27.87     dependent: set(hyper_res).
% 27.73/27.87     dependent: set(unit_deletion).
% 27.73/27.87     dependent: set(factor).
% 27.73/27.87  
% 27.73/27.87  ------------> process usable:
% 27.73/27.87  ** KEPT (pick-wt=8): 1 [] -l(A,B)|product(A,B)=A.
% 27.73/27.87  ** KEPT (pick-wt=8): 2 [] -l(A,B)|product(B,A)=B.
% 27.73/27.87  ** KEPT (pick-wt=13): 3 [] l(A,B)|product(A,B)!=A|product(B,A)!=B.
% 27.73/27.87  ** KEPT (pick-wt=8): 4 [] -r(A,B)|product(A,B)=B.
% 27.73/27.87  ** KEPT (pick-wt=8): 5 [] -r(A,B)|product(B,A)=A.
% 27.73/27.87  ** KEPT (pick-wt=13): 6 [] r(A,B)|product(A,B)!=B|product(B,A)!=A.
% 27.73/27.87  ** KEPT (pick-wt=8): 7 [] -d(A,B)|r(A,$f1(A,B)).
% 27.73/27.87  ** KEPT (pick-wt=8): 8 [] -d(A,B)|l($f1(A,B),B).
% 27.73/27.87  ** KEPT (pick-wt=9): 9 [] d(A,B)| -r(A,C)| -l(C,B).
% 27.73/27.87  ** KEPT (pick-wt=17): 10 [] -d($c2,$c1)|product($c2,product($c1,$c2))!=$c2|product($c1,product($c2,$c1))!=$c1.
% 27.73/27.87  
% 27.73/27.87  ------------> process sos:
% 27.73/27.87  ** KEPT (pick-wt=3): 13 [] A=A.
% 27.73/27.87  ** KEPT (pick-wt=11): 14 [] product(product(A,B),C)=product(A,product(B,C)).
% 27.73/27.87  ---> New Demodulator: 15 [new_demod,14] product(product(A,B),C)=product(A,product(B,C)).
% 27.73/27.87  ** KEPT (pick-wt=5): 16 [] product(A,A)=A.
% 27.73/27.87  ---> New Demodulator: 17 [new_demod,16] product(A,A)=A.
% 27.73/27.87  ** KEPT (pick-wt=10): 18 [] d($c2,$c1)|product($c2,product($c1,$c2))=$c2.
% 27.73/27.87  ** KEPT (pick-wt=10): 19 [] d($c2,$c1)|product($c1,product($c2,$c1))=$c1.
% 27.73/27.87    Following clause subsumed by 13 during input processing: 0 [copy,13,flip.1] A=A.
% 27.73/27.87  >>>> Starting back demodulation with 15.
% 27.73/27.87  >>>> Starting back demodulation with 17.
% 27.73/27.87      >> back demodulating 12 with 17.
% 27.73/27.87      >> back demodulating 11 with 17.
% 27.73/27.87  
% 27.73/27.87  ======= end of input processing =======
% 27.73/27.87  
% 27.73/27.87  =========== start of search ===========
% 27.73/27.87  
% 27.73/27.87  
% 27.73/27.87  Resetting weight limit to 12.
% 27.73/27.87  
% 27.73/27.87  
% 27.73/27.87  Resetting weight limit to 12.
% 27.73/27.87  
% 27.73/27.87  sos_size=2518
% 27.73/27.87  
% 27.73/27.87  
% 27.73/27.87  Resetting weight limit to 11.
% 27.73/27.87  
% 27.73/27.87  
% 27.73/27.87  Resetting weight limit to 11.
% 27.73/27.87  
% 27.73/27.87  sos_size=2632
% 27.73/27.87  
% 27.73/27.87  -- HEY sandbox, WE HAVE A PROOF!! -- 
% 27.73/27.87  
% 27.73/27.87  ----> UNIT CONFLICT at  25.76 sec ----> 4553 [binary,4552.1,948.1] $F.
% 27.73/27.87  
% 27.73/27.87  Length of proof is 56.  Level of proof is 14.
% 27.73/27.87  
% 27.73/27.87  ---------------- PROOF ----------------
% 27.73/27.87  % SZS status Theorem
% 27.73/27.87  % SZS output start Refutation
% See solution above
% 27.73/27.87  ------------ end of proof -------------
% 27.73/27.87  
% 27.73/27.87  
% 27.73/27.87  Search stopped by max_proofs option.
% 27.73/27.87  
% 27.73/27.87  
% 27.73/27.87  Search stopped by max_proofs option.
% 27.73/27.87  
% 27.73/27.87  ============ end of search ============
% 27.73/27.87  
% 27.73/27.87  -------------- statistics -------------
% 27.73/27.87  clauses given               1232
% 27.73/27.87  clauses generated         469497
% 27.73/27.87  clauses kept                4462
% 27.73/27.87  clauses forward subsumed   31502
% 27.73/27.87  clauses back subsumed        898
% 27.73/27.87  Kbytes malloced             4882
% 27.73/27.87  
% 27.73/27.87  ----------- times (seconds) -----------
% 27.73/27.87  user CPU time         25.76          (0 hr, 0 min, 25 sec)
% 27.73/27.87  system CPU time        0.01          (0 hr, 0 min, 0 sec)
% 27.73/27.87  wall-clock time       28             (0 hr, 0 min, 28 sec)
% 27.73/27.87  
% 27.73/27.87  That finishes the proof of the theorem.
% 27.73/27.87  
% 27.73/27.87  Process 20885 finished Wed Jul 27 05:44:54 2022
% 27.73/27.87  Otter interrupted
% 27.73/27.87  PROOF FOUND
%------------------------------------------------------------------------------