TSTP Solution File: GRP124-1.004 by Prover9---1109a

View Problem - Process Solution

%------------------------------------------------------------------------------
% File     : Prover9---1109a
% Problem  : GRP124-1.004 : TPTP v8.1.0. Released v1.2.0.
% Transfm  : none
% Format   : tptp:raw
% Command  : tptp2X_and_run_prover9 %d %s

% Computer : n016.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 : Sat Jul 16 11:17:18 EDT 2022

% Result   : Unsatisfiable 0.74s 1.07s
% Output   : Refutation 0.74s
% Verified : 
% SZS Type : -

% Comments : 
%------------------------------------------------------------------------------
%----WARNING: Could not form TPTP format derivation
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.07/0.12  % Problem  : GRP124-1.004 : TPTP v8.1.0. Released v1.2.0.
% 0.07/0.13  % Command  : tptp2X_and_run_prover9 %d %s
% 0.14/0.34  % Computer : n016.cluster.edu
% 0.14/0.34  % Model    : x86_64 x86_64
% 0.14/0.34  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.14/0.34  % Memory   : 8042.1875MB
% 0.14/0.34  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.14/0.34  % CPULimit : 300
% 0.14/0.34  % WCLimit  : 600
% 0.14/0.34  % DateTime : Mon Jun 13 22:24:30 EDT 2022
% 0.14/0.34  % CPUTime  : 
% 0.45/0.99  ============================== Prover9 ===============================
% 0.45/0.99  Prover9 (32) version 2009-11A, November 2009.
% 0.45/0.99  Process 26856 was started by sandbox on n016.cluster.edu,
% 0.45/0.99  Mon Jun 13 22:24:30 2022
% 0.45/0.99  The command was "/export/starexec/sandbox/solver/bin/prover9 -t 300 -f /tmp/Prover9_26520_n016.cluster.edu".
% 0.45/0.99  ============================== end of head ===========================
% 0.45/0.99  
% 0.45/0.99  ============================== INPUT =================================
% 0.45/0.99  
% 0.45/0.99  % Reading from file /tmp/Prover9_26520_n016.cluster.edu
% 0.45/0.99  
% 0.45/0.99  set(prolog_style_variables).
% 0.45/0.99  set(auto2).
% 0.45/0.99      % set(auto2) -> set(auto).
% 0.45/0.99      % set(auto) -> set(auto_inference).
% 0.45/0.99      % set(auto) -> set(auto_setup).
% 0.45/0.99      % set(auto_setup) -> set(predicate_elim).
% 0.45/0.99      % set(auto_setup) -> assign(eq_defs, unfold).
% 0.45/0.99      % set(auto) -> set(auto_limits).
% 0.45/0.99      % set(auto_limits) -> assign(max_weight, "100.000").
% 0.45/0.99      % set(auto_limits) -> assign(sos_limit, 20000).
% 0.45/0.99      % set(auto) -> set(auto_denials).
% 0.45/0.99      % set(auto) -> set(auto_process).
% 0.45/0.99      % set(auto2) -> assign(new_constants, 1).
% 0.45/0.99      % set(auto2) -> assign(fold_denial_max, 3).
% 0.45/0.99      % set(auto2) -> assign(max_weight, "200.000").
% 0.45/0.99      % set(auto2) -> assign(max_hours, 1).
% 0.45/0.99      % assign(max_hours, 1) -> assign(max_seconds, 3600).
% 0.45/0.99      % set(auto2) -> assign(max_seconds, 0).
% 0.45/0.99      % set(auto2) -> assign(max_minutes, 5).
% 0.45/0.99      % assign(max_minutes, 5) -> assign(max_seconds, 300).
% 0.45/0.99      % set(auto2) -> set(sort_initial_sos).
% 0.45/0.99      % set(auto2) -> assign(sos_limit, -1).
% 0.45/0.99      % set(auto2) -> assign(lrs_ticks, 3000).
% 0.45/0.99      % set(auto2) -> assign(max_megs, 400).
% 0.45/0.99      % set(auto2) -> assign(stats, some).
% 0.45/0.99      % set(auto2) -> clear(echo_input).
% 0.45/0.99      % set(auto2) -> set(quiet).
% 0.45/0.99      % set(auto2) -> clear(print_initial_clauses).
% 0.45/0.99      % set(auto2) -> clear(print_given).
% 0.45/0.99  assign(lrs_ticks,-1).
% 0.45/0.99  assign(sos_limit,10000).
% 0.45/0.99  assign(order,kbo).
% 0.45/0.99  set(lex_order_vars).
% 0.45/0.99  clear(print_given).
% 0.45/0.99  
% 0.45/0.99  % formulas(sos).  % not echoed (23 formulas)
% 0.45/0.99  
% 0.45/0.99  ============================== end of input ==========================
% 0.45/0.99  
% 0.45/0.99  % From the command line: assign(max_seconds, 300).
% 0.45/0.99  
% 0.45/0.99  ============================== PROCESS NON-CLAUSAL FORMULAS ==========
% 0.45/0.99  
% 0.45/0.99  % Formulas that are not ordinary clauses:
% 0.45/0.99  
% 0.45/0.99  ============================== end of process non-clausal formulas ===
% 0.45/0.99  
% 0.45/0.99  ============================== PROCESS INITIAL CLAUSES ===============
% 0.45/0.99  
% 0.45/0.99  ============================== PREDICATE ELIMINATION =================
% 0.45/0.99  1 -product(A,B,C) | -product(A,B,D) | equalish(C,D) # label(product_total_function2) # label(axiom).  [assumption].
% 0.45/0.99  2 -equalish(e_1,e_2) # label(e_1_is_not_e_2) # label(axiom).  [assumption].
% 0.45/0.99  3 -equalish(e_1,e_3) # label(e_1_is_not_e_3) # label(axiom).  [assumption].
% 0.45/0.99  4 -equalish(e_1,e_4) # label(e_1_is_not_e_4) # label(axiom).  [assumption].
% 0.45/0.99  5 -equalish(e_2,e_1) # label(e_2_is_not_e_1) # label(axiom).  [assumption].
% 0.45/0.99  6 -equalish(e_2,e_3) # label(e_2_is_not_e_3) # label(axiom).  [assumption].
% 0.45/0.99  7 -equalish(e_2,e_4) # label(e_2_is_not_e_4) # label(axiom).  [assumption].
% 0.45/0.99  8 -equalish(e_3,e_1) # label(e_3_is_not_e_1) # label(axiom).  [assumption].
% 0.45/0.99  9 -equalish(e_3,e_2) # label(e_3_is_not_e_2) # label(axiom).  [assumption].
% 0.45/0.99  10 -equalish(e_3,e_4) # label(e_3_is_not_e_4) # label(axiom).  [assumption].
% 0.45/0.99  11 -equalish(e_4,e_1) # label(e_4_is_not_e_1) # label(axiom).  [assumption].
% 0.45/0.99  12 -equalish(e_4,e_2) # label(e_4_is_not_e_2) # label(axiom).  [assumption].
% 0.45/0.99  13 -equalish(e_4,e_3) # label(e_4_is_not_e_3) # label(axiom).  [assumption].
% 0.45/0.99  Derived: -product(A,B,e_1) | -product(A,B,e_2).  [resolve(1,c,2,a)].
% 0.45/0.99  Derived: -product(A,B,e_1) | -product(A,B,e_3).  [resolve(1,c,3,a)].
% 0.45/0.99  Derived: -product(A,B,e_1) | -product(A,B,e_4).  [resolve(1,c,4,a)].
% 0.45/0.99  Derived: -product(A,B,e_2) | -product(A,B,e_3).  [resolve(1,c,6,a)].
% 0.45/0.99  Derived: -product(A,B,e_2) | -product(A,B,e_4).  [resolve(1,c,7,a)].
% 0.45/0.99  Derived: -product(A,B,e_3) | -product(A,B,e_4).  [resolve(1,c,10,a)].
% 0.45/0.99  14 -product(A,B,C) | -product(A,D,C) | equalish(B,D) # label(product_right_cancellation) # label(axiom).  [assumption].
% 0.45/0.99  Derived: -product(A,e_1,B) | -product(A,e_2,B).  [resolve(14,c,2,a)].
% 0.45/0.99  Derived: -product(A,e_1,B) | -product(A,e_3,B).  [resolve(14,c,3,a)].
% 0.45/0.99  Derived: -product(A,e_1,B) | -product(A,e_4,B).  [resolve(14,c,4,a)].
% 0.74/1.07  Derived: -product(A,e_2,B) | -product(A,e_3,B).  [resolve(14,c,6,a)].
% 0.74/1.07  Derived: -product(A,e_2,B) | -product(A,e_4,B).  [resolve(14,c,7,a)].
% 0.74/1.07  Derived: -product(A,e_3,B) | -product(A,e_4,B).  [resolve(14,c,10,a)].
% 0.74/1.07  15 -product(A,B,C) | -product(D,B,C) | equalish(A,D) # label(product_left_cancellation) # label(axiom).  [assumption].
% 0.74/1.07  Derived: -product(e_1,A,B) | -product(e_2,A,B).  [resolve(15,c,2,a)].
% 0.74/1.07  Derived: -product(e_1,A,B) | -product(e_3,A,B).  [resolve(15,c,3,a)].
% 0.74/1.07  Derived: -product(e_1,A,B) | -product(e_4,A,B).  [resolve(15,c,4,a)].
% 0.74/1.07  Derived: -product(e_2,A,B) | -product(e_3,A,B).  [resolve(15,c,6,a)].
% 0.74/1.07  Derived: -product(e_2,A,B) | -product(e_4,A,B).  [resolve(15,c,7,a)].
% 0.74/1.07  Derived: -product(e_3,A,B) | -product(e_4,A,B).  [resolve(15,c,10,a)].
% 0.74/1.07  16 -product(A,B,C) | -product(D,E,C) | -product(F,A,B) | -product(F,D,E) | equalish(A,D) # label(qg2_1) # label(negated_conjecture).  [assumption].
% 0.74/1.07  Derived: -product(e_1,A,B) | -product(e_2,C,B) | -product(D,e_1,A) | -product(D,e_2,C).  [resolve(16,e,2,a)].
% 0.74/1.07  Derived: -product(e_1,A,B) | -product(e_3,C,B) | -product(D,e_1,A) | -product(D,e_3,C).  [resolve(16,e,3,a)].
% 0.74/1.07  Derived: -product(e_1,A,B) | -product(e_4,C,B) | -product(D,e_1,A) | -product(D,e_4,C).  [resolve(16,e,4,a)].
% 0.74/1.07  Derived: -product(e_2,A,B) | -product(e_3,C,B) | -product(D,e_2,A) | -product(D,e_3,C).  [resolve(16,e,6,a)].
% 0.74/1.07  Derived: -product(e_2,A,B) | -product(e_4,C,B) | -product(D,e_2,A) | -product(D,e_4,C).  [resolve(16,e,7,a)].
% 0.74/1.07  Derived: -product(e_3,A,B) | -product(e_4,C,B) | -product(D,e_3,A) | -product(D,e_4,C).  [resolve(16,e,10,a)].
% 0.74/1.07  17 -product(A,B,C) | -product(D,E,C) | -product(F,A,B) | -product(F,D,E) | equalish(B,E) # label(qg2_2) # label(negated_conjecture).  [assumption].
% 0.74/1.07  Derived: -product(A,e_1,B) | -product(C,e_2,B) | -product(D,A,e_1) | -product(D,C,e_2).  [resolve(17,e,2,a)].
% 0.74/1.07  Derived: -product(A,e_1,B) | -product(C,e_3,B) | -product(D,A,e_1) | -product(D,C,e_3).  [resolve(17,e,3,a)].
% 0.74/1.07  Derived: -product(A,e_1,B) | -product(C,e_4,B) | -product(D,A,e_1) | -product(D,C,e_4).  [resolve(17,e,4,a)].
% 0.74/1.07  Derived: -product(A,e_2,B) | -product(C,e_3,B) | -product(D,A,e_2) | -product(D,C,e_3).  [resolve(17,e,6,a)].
% 0.74/1.07  Derived: -product(A,e_2,B) | -product(C,e_4,B) | -product(D,A,e_2) | -product(D,C,e_4).  [resolve(17,e,7,a)].
% 0.74/1.07  Derived: -product(A,e_3,B) | -product(C,e_4,B) | -product(D,A,e_3) | -product(D,C,e_4).  [resolve(17,e,10,a)].
% 0.74/1.07  
% 0.74/1.07  ============================== end predicate elimination =============
% 0.74/1.07  
% 0.74/1.07  Auto_denials:  (non-Horn, no changes).
% 0.74/1.07  
% 0.74/1.07  Term ordering decisions:
% 0.74/1.07  Function symbol KB weights:  e_1=1. e_2=1. e_3=1. e_4=1.
% 0.74/1.07  
% 0.74/1.07  ============================== end of process initial clauses ========
% 0.74/1.07  
% 0.74/1.07  ============================== CLAUSES FOR SEARCH ====================
% 0.74/1.07  
% 0.74/1.07  ============================== end of clauses for search =============
% 0.74/1.07  
% 0.74/1.07  ============================== SEARCH ================================
% 0.74/1.07  
% 0.74/1.07  % Starting search at 0.01 seconds.
% 0.74/1.07  
% 0.74/1.07  ============================== PROOF =================================
% 0.74/1.07  % SZS status Unsatisfiable
% 0.74/1.07  % SZS output start Refutation
% 0.74/1.07  
% 0.74/1.07  % Proof 1 at 0.08 (+ 0.01) seconds.
% 0.74/1.07  % Length of proof is 79.
% 0.74/1.07  % Level of proof is 11.
% 0.74/1.07  % Maximum clause weight is 20.000.
% 0.74/1.07  % Given clauses 250.
% 0.74/1.07  
% 0.74/1.07  2 -equalish(e_1,e_2) # label(e_1_is_not_e_2) # label(axiom).  [assumption].
% 0.74/1.07  3 -equalish(e_1,e_3) # label(e_1_is_not_e_3) # label(axiom).  [assumption].
% 0.74/1.07  4 -equalish(e_1,e_4) # label(e_1_is_not_e_4) # label(axiom).  [assumption].
% 0.74/1.07  6 -equalish(e_2,e_3) # label(e_2_is_not_e_3) # label(axiom).  [assumption].
% 0.74/1.07  7 -equalish(e_2,e_4) # label(e_2_is_not_e_4) # label(axiom).  [assumption].
% 0.74/1.07  10 -equalish(e_3,e_4) # label(e_3_is_not_e_4) # label(axiom).  [assumption].
% 0.74/1.07  14 -product(A,B,C) | -product(A,D,C) | equalish(B,D) # label(product_right_cancellation) # label(axiom).  [assumption].
% 0.74/1.07  15 -product(A,B,C) | -product(D,B,C) | equalish(A,D) # label(product_left_cancellation) # label(axiom).  [assumption].
% 0.74/1.07  17 -product(A,B,C) | -product(D,E,C) | -product(F,A,B) | -product(F,D,E) | equalish(B,E) # label(qg2_2) # label(negated_conjecture).  [assumption].
% 0.74/1.07  18 group_element(e_1) # label(element_1) # label(axiom).  [assumption].
% 0.74/1.07  19 group_element(e_2) # label(element_2) # label(axiom).  [assumption].
% 0.74/1.07  20 group_element(e_3) # label(element_3) # label(axiom).  [assumption].
% 0.74/1.07  21 group_element(e_4) # label(element_4) # label(axiom).  [assumption].
% 0.74/1.07  22 product(A,A,A) # label(product_idempotence) # label(axiom).  [assumption].
% 0.74/1.07  23 -group_element(A) | -group_element(B) | product(A,B,e_1) | product(A,B,e_2) | product(A,B,e_3) | product(A,B,e_4) # label(product_total_function1) # label(axiom).  [assumption].
% 0.74/1.07  30 -product(A,e_1,B) | -product(A,e_2,B).  [resolve(14,c,2,a)].
% 0.74/1.07  31 -product(A,e_1,B) | -product(A,e_3,B).  [resolve(14,c,3,a)].
% 0.74/1.07  32 -product(A,e_1,B) | -product(A,e_4,B).  [resolve(14,c,4,a)].
% 0.74/1.07  33 -product(A,e_2,B) | -product(A,e_3,B).  [resolve(14,c,6,a)].
% 0.74/1.07  34 -product(A,e_2,B) | -product(A,e_4,B).  [resolve(14,c,7,a)].
% 0.74/1.07  35 -product(A,e_3,B) | -product(A,e_4,B).  [resolve(14,c,10,a)].
% 0.74/1.07  36 -product(e_1,A,B) | -product(e_2,A,B).  [resolve(15,c,2,a)].
% 0.74/1.07  37 -product(e_1,A,B) | -product(e_3,A,B).  [resolve(15,c,3,a)].
% 0.74/1.07  38 -product(e_1,A,B) | -product(e_4,A,B).  [resolve(15,c,4,a)].
% 0.74/1.07  39 -product(e_2,A,B) | -product(e_3,A,B).  [resolve(15,c,6,a)].
% 0.74/1.07  40 -product(e_2,A,B) | -product(e_4,A,B).  [resolve(15,c,7,a)].
% 0.74/1.07  41 -product(e_3,A,B) | -product(e_4,A,B).  [resolve(15,c,10,a)].
% 0.74/1.07  48 -product(A,e_1,B) | -product(C,e_2,B) | -product(D,A,e_1) | -product(D,C,e_2).  [resolve(17,e,2,a)].
% 0.74/1.07  49 -product(A,e_1,B) | -product(C,e_3,B) | -product(D,A,e_1) | -product(D,C,e_3).  [resolve(17,e,3,a)].
% 0.74/1.07  52 -product(A,e_2,B) | -product(C,e_4,B) | -product(D,A,e_2) | -product(D,C,e_4).  [resolve(17,e,7,a)].
% 0.74/1.07  53 -product(A,e_3,B) | -product(C,e_4,B) | -product(D,A,e_3) | -product(D,C,e_4).  [resolve(17,e,10,a)].
% 0.74/1.07  98 -product(A,e_2,e_4) | -product(e_4,A,e_2).  [factor(52,b,d),unit_del(b,22)].
% 0.74/1.07  102 -product(A,e_3,e_4) | -product(e_4,A,e_3).  [factor(53,b,d),unit_del(b,22)].
% 0.74/1.07  103 -group_element(A) | product(e_4,A,e_1) | product(e_4,A,e_2) | product(e_4,A,e_3) | product(e_4,A,e_4).  [resolve(23,a,21,a)].
% 0.74/1.07  104 -group_element(A) | product(e_3,A,e_1) | product(e_3,A,e_2) | product(e_3,A,e_3) | product(e_3,A,e_4).  [resolve(23,a,20,a)].
% 0.74/1.07  105 -group_element(A) | product(e_2,A,e_1) | product(e_2,A,e_2) | product(e_2,A,e_3) | product(e_2,A,e_4).  [resolve(23,a,19,a)].
% 0.74/1.07  106 -group_element(A) | product(e_1,A,e_1) | product(e_1,A,e_2) | product(e_1,A,e_3) | product(e_1,A,e_4).  [resolve(23,a,18,a)].
% 0.74/1.07  124 -product(e_1,e_2,e_1).  [ur(30,a,22,a)].
% 0.74/1.07  126 -product(e_1,e_3,e_1).  [ur(31,a,22,a)].
% 0.74/1.07  127 -product(e_4,e_1,e_4).  [resolve(32,b,22,a)].
% 0.74/1.07  129 -product(e_3,e_2,e_3).  [resolve(33,b,22,a)].
% 0.74/1.07  130 -product(e_2,e_3,e_2).  [ur(33,a,22,a)].
% 0.74/1.07  131 -product(e_4,e_2,e_4).  [resolve(34,b,22,a)].
% 0.74/1.07  133 -product(e_4,e_3,e_4).  [resolve(35,b,22,a)].
% 0.74/1.07  135 -product(e_1,e_2,e_2).  [resolve(36,b,22,a)].
% 0.74/1.07  137 -product(e_1,e_3,e_3).  [resolve(37,b,22,a)].
% 0.74/1.07  140 -product(e_4,e_1,e_1).  [ur(38,a,22,a)].
% 0.74/1.07  141 -product(e_2,e_3,e_3).  [resolve(39,b,22,a)].
% 0.74/1.07  142 -product(e_3,e_2,e_2).  [ur(39,a,22,a)].
% 0.74/1.07  144 -product(e_4,e_2,e_2).  [ur(40,a,22,a)].
% 0.74/1.07  146 -product(e_4,e_3,e_3).  [ur(41,a,22,a)].
% 0.74/1.07  173 -product(e_1,e_1,A) | -product(B,e_2,A) | -product(e_1,B,e_2).  [resolve(48,c,22,a)].
% 0.74/1.07  177 -product(e_1,e_1,A) | -product(B,e_3,A) | -product(e_1,B,e_3).  [resolve(49,c,22,a)].
% 0.74/1.07  195 product(e_4,e_3,e_1) | product(e_4,e_3,e_2).  [resolve(103,a,20,a),unit_del(c,146),unit_del(d,133)].
% 0.74/1.07  196 product(e_4,e_2,e_1) | product(e_4,e_2,e_3).  [resolve(103,a,19,a),unit_del(b,144),unit_del(d,131)].
% 0.74/1.07  197 product(e_4,e_1,e_2) | product(e_4,e_1,e_3).  [resolve(103,a,18,a),unit_del(a,140),unit_del(d,127)].
% 0.74/1.07  198 product(e_4,e_3,e_1) | -product(e_3,e_2,e_4).  [resolve(195,b,98,b)].
% 0.74/1.07  213 product(e_4,e_3,e_1) | -product(e_4,e_1,e_2).  [resolve(195,b,31,b)].
% 0.74/1.07  214 product(e_4,e_2,e_1) | -product(e_2,e_3,e_4).  [resolve(196,b,102,b)].
% 0.74/1.07  230 product(e_4,e_1,e_2) | -product(e_1,e_3,e_4).  [resolve(197,b,102,b)].
% 0.74/1.07  246 product(e_3,e_2,e_1) | product(e_3,e_2,e_4).  [resolve(104,a,19,a),unit_del(b,142),unit_del(c,129)].
% 0.74/1.07  249 product(e_2,e_3,e_1) | product(e_2,e_3,e_4).  [resolve(105,a,20,a),unit_del(b,130),unit_del(c,141)].
% 0.74/1.07  253 product(e_1,e_3,e_2) | product(e_1,e_3,e_4).  [resolve(106,a,20,a),unit_del(a,126),unit_del(c,137)].
% 0.74/1.07  254 product(e_1,e_2,e_3) | product(e_1,e_2,e_4).  [resolve(106,a,19,a),unit_del(a,124),unit_del(b,135)].
% 0.74/1.07  272 product(e_3,e_2,e_1) | product(e_4,e_3,e_1).  [resolve(246,b,198,b)].
% 0.74/1.07  287 product(e_3,e_2,e_1) | -product(e_1,e_2,e_4).  [resolve(246,b,37,b)].
% 0.74/1.07  321 product(e_2,e_3,e_1) | product(e_4,e_2,e_1).  [resolve(249,b,214,b)].
% 0.74/1.07  382 product(e_1,e_3,e_2) | product(e_4,e_1,e_2).  [resolve(253,b,230,b)].
% 0.74/1.07  441 product(e_3,e_2,e_1) | -product(e_4,e_2,e_1).  [resolve(272,b,33,b)].
% 0.74/1.07  443 product(e_3,e_2,e_1) | product(e_1,e_2,e_3).  [resolve(287,b,254,b)].
% 0.74/1.07  490 product(e_2,e_3,e_1) | -product(e_3,e_2,e_1).  [resolve(321,b,41,b)].
% 0.74/1.07  517 product(e_1,e_3,e_2) | product(e_4,e_3,e_1).  [resolve(382,b,213,b)].
% 0.74/1.07  552 product(e_3,e_2,e_1) | product(e_2,e_3,e_1).  [resolve(441,b,321,b)].
% 0.74/1.07  576 product(e_1,e_2,e_3) | -product(e_1,e_3,e_2).  [resolve(443,a,173,b),unit_del(b,22)].
% 0.74/1.07  791 product(e_1,e_3,e_2) | -product(e_2,e_3,e_1).  [resolve(517,b,40,b)].
% 0.74/1.07  827 product(e_2,e_3,e_1).  [resolve(552,a,490,b),merge(b)].
% 0.74/1.07  828 product(e_1,e_3,e_2).  [back_unit_del(791),unit_del(b,827)].
% 0.74/1.07  834 product(e_1,e_2,e_3).  [back_unit_del(576),unit_del(b,828)].
% 0.74/1.07  839 $F.  [resolve(827,a,177,b),unit_del(a,22),unit_del(b,834)].
% 0.74/1.07  
% 0.74/1.07  % SZS output end Refutation
% 0.74/1.07  ============================== end of proof ==========================
% 0.74/1.07  
% 0.74/1.07  ============================== STATISTICS ============================
% 0.74/1.07  
% 0.74/1.07  Given=250. Generated=1901. Kept=821. proofs=1.
% 0.74/1.07  Usable=154. Sos=11. Demods=0. Limbo=0, Disabled=709. Hints=0.
% 0.74/1.07  Megabytes=0.50.
% 0.74/1.07  User_CPU=0.08, System_CPU=0.01, Wall_clock=0.
% 0.74/1.07  
% 0.74/1.07  ============================== end of statistics =====================
% 0.74/1.07  
% 0.74/1.07  ============================== end of search =========================
% 0.74/1.07  
% 0.74/1.07  THEOREM PROVED
% 0.74/1.07  % SZS status Unsatisfiable
% 0.74/1.07  
% 0.74/1.07  Exiting with 1 proof.
% 0.74/1.07  
% 0.74/1.07  Process 26856 exit (max_proofs) Mon Jun 13 22:24:30 2022
% 0.74/1.07  Prover9 interrupted
%------------------------------------------------------------------------------