TSTP Solution File: LAT010-1 by SPASS---3.9

View Problem - Process Solution

%------------------------------------------------------------------------------
% File     : SPASS---3.9
% Problem  : LAT010-1 : TPTP v8.1.0. Released v2.2.0.
% Transfm  : none
% Format   : tptp
% Command  : run_spass %d %s

% Computer : n004.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 : Sun Jul 17 06:48:34 EDT 2022

% Result   : Unsatisfiable 2.07s 2.28s
% Output   : Refutation 2.13s
% Verified : 
% SZS Type : Refutation
%            Derivation depth      :   21
%            Number of leaves      :   10
% Syntax   : Number of clauses     :   86 (  86 unt;   0 nHn;  86 RR)
%            Number of literals    :   86 (   0 equ;   5 neg)
%            Maximal clause size   :    1 (   1 avg)
%            Maximal term depth    :    9 (   2 avg)
%            Number of predicates  :    2 (   1 usr;   1 prp; 0-2 aty)
%            Number of functors    :   11 (  11 usr;   9 con; 0-2 aty)
%            Number of variables   :    0 (   0 sgn)

% Comments : 
%------------------------------------------------------------------------------
cnf(1,axiom,
    equal(join(meet(u,join(v,meet(u,w))),meet(u,join(meet(u,v),meet(w,x)))),meet(u,join(v,meet(w,join(u,x))))),
    file('LAT010-1.p',unknown),
    [] ).

cnf(3,axiom,
    equal(join(meet(u,join(v,meet(w,u))),meet(v,join(w,u))),meet(join(v,meet(w,u)),join(u,meet(v,w)))),
    file('LAT010-1.p',unknown),
    [] ).

cnf(4,axiom,
    ~ equal(meet(meet(a,meet(join(b,c),join(b,d))),join(meet(a,join(b,meet(c,d))),join(meet(a,c),meet(a,d)))),meet(a,meet(join(b,c),join(b,d)))),
    file('LAT010-1.p',unknown),
    [] ).

cnf(5,axiom,
    equal(meet(u,u),u),
    file('LAT010-1.p',unknown),
    [] ).

cnf(7,axiom,
    equal(meet(u,join(u,v)),u),
    file('LAT010-1.p',unknown),
    [] ).

cnf(8,axiom,
    equal(join(u,meet(u,v)),u),
    file('LAT010-1.p',unknown),
    [] ).

cnf(9,axiom,
    equal(meet(u,v),meet(v,u)),
    file('LAT010-1.p',unknown),
    [] ).

cnf(10,axiom,
    equal(join(u,v),join(v,u)),
    file('LAT010-1.p',unknown),
    [] ).

cnf(11,axiom,
    equal(meet(meet(u,v),w),meet(u,meet(v,w))),
    file('LAT010-1.p',unknown),
    [] ).

cnf(12,axiom,
    equal(join(join(u,v),w),join(u,join(v,w))),
    file('LAT010-1.p',unknown),
    [] ).

cnf(13,plain,
    equal(join(meet(u,join(v,w)),meet(w,join(u,meet(v,w)))),meet(join(u,meet(v,w)),join(w,meet(u,v)))),
    inference(rew,[status(thm),theory(equality)],[10,3]),
    [iquote('0:Rew:10.0,3.0')] ).

cnf(14,plain,
    ~ equal(meet(a,meet(join(b,c),meet(join(b,d),join(meet(a,c),join(meet(a,d),meet(a,join(b,meet(c,d)))))))),meet(a,meet(join(b,c),join(b,d)))),
    inference(rew,[status(thm),theory(equality)],[11,4,12,10]),
    [iquote('0:Rew:11.0,4.0,11.0,4.0,12.0,4.0,10.0,4.0')] ).

cnf(24,plain,
    equal(meet(u,join(v,u)),u),
    inference(spr,[status(thm),theory(equality)],[10,7]),
    [iquote('0:SpR:10.0,7.0')] ).

cnf(32,plain,
    equal(join(u,meet(v,u)),u),
    inference(spr,[status(thm),theory(equality)],[9,8]),
    [iquote('0:SpR:9.0,8.0')] ).

cnf(43,plain,
    equal(meet(meet(u,v),u),meet(u,v)),
    inference(spr,[status(thm),theory(equality)],[8,24]),
    [iquote('0:SpR:8.0,24.0')] ).

cnf(46,plain,
    equal(meet(u,meet(u,v)),meet(u,v)),
    inference(rew,[status(thm),theory(equality)],[9,43]),
    [iquote('0:Rew:9.0,43.0')] ).

cnf(53,plain,
    equal(join(join(u,v),u),join(u,v)),
    inference(spr,[status(thm),theory(equality)],[7,32]),
    [iquote('0:SpR:7.0,32.0')] ).

cnf(54,plain,
    equal(join(join(u,v),v),join(u,v)),
    inference(spr,[status(thm),theory(equality)],[24,32]),
    [iquote('0:SpR:24.0,32.0')] ).

cnf(57,plain,
    equal(join(u,join(u,v)),join(u,v)),
    inference(rew,[status(thm),theory(equality)],[10,53]),
    [iquote('0:Rew:10.0,53.0')] ).

cnf(58,plain,
    equal(join(u,join(v,u)),join(v,u)),
    inference(rew,[status(thm),theory(equality)],[10,54]),
    [iquote('0:Rew:10.0,54.0')] ).

cnf(72,plain,
    equal(join(u,join(v,w)),join(w,join(u,v))),
    inference(spr,[status(thm),theory(equality)],[12,10]),
    [iquote('0:SpR:12.0,10.0')] ).

cnf(75,plain,
    equal(meet(u,join(v,join(w,u))),u),
    inference(spr,[status(thm),theory(equality)],[12,24]),
    [iquote('0:SpR:12.0,24.0')] ).

cnf(78,plain,
    equal(join(u,join(meet(u,v),w)),join(u,w)),
    inference(spr,[status(thm),theory(equality)],[8,12]),
    [iquote('0:SpR:8.0,12.0')] ).

cnf(142,plain,
    equal(meet(meet(u,v),join(w,u)),meet(u,v)),
    inference(spr,[status(thm),theory(equality)],[8,75]),
    [iquote('0:SpR:8.0,75.0')] ).

cnf(144,plain,
    equal(meet(u,join(v,join(u,w))),u),
    inference(spr,[status(thm),theory(equality)],[10,75]),
    [iquote('0:SpR:10.0,75.0')] ).

cnf(158,plain,
    equal(meet(u,meet(v,join(w,u))),meet(u,v)),
    inference(rew,[status(thm),theory(equality)],[11,142]),
    [iquote('0:Rew:11.0,142.0')] ).

cnf(164,plain,
    equal(meet(u,meet(v,w)),meet(w,meet(u,v))),
    inference(spr,[status(thm),theory(equality)],[11,9]),
    [iquote('0:SpR:11.0,9.0')] ).

cnf(169,plain,
    equal(meet(u,meet(v,join(w,join(x,meet(u,v))))),meet(u,v)),
    inference(spr,[status(thm),theory(equality)],[11,75]),
    [iquote('0:SpR:11.0,75.0')] ).

cnf(173,plain,
    equal(join(u,meet(v,meet(w,u))),u),
    inference(spr,[status(thm),theory(equality)],[11,32]),
    [iquote('0:SpR:11.0,32.0')] ).

cnf(177,plain,
    equal(meet(meet(u,v),w),meet(v,meet(u,w))),
    inference(spr,[status(thm),theory(equality)],[9,11]),
    [iquote('0:SpR:9.0,11.0')] ).

cnf(178,plain,
    equal(meet(u,meet(join(u,v),w)),meet(u,w)),
    inference(spr,[status(thm),theory(equality)],[7,11]),
    [iquote('0:SpR:7.0,11.0')] ).

cnf(179,plain,
    equal(meet(u,meet(join(v,u),w)),meet(u,w)),
    inference(spr,[status(thm),theory(equality)],[24,11]),
    [iquote('0:SpR:24.0,11.0')] ).

cnf(185,plain,
    equal(meet(u,meet(v,w)),meet(v,meet(u,w))),
    inference(rew,[status(thm),theory(equality)],[11,177]),
    [iquote('0:Rew:11.0,177.0')] ).

cnf(234,plain,
    equal(join(join(u,v),meet(w,u)),join(u,v)),
    inference(spr,[status(thm),theory(equality)],[7,173]),
    [iquote('0:SpR:7.0,173.0')] ).

cnf(251,plain,
    equal(join(u,join(v,meet(w,u))),join(u,v)),
    inference(rew,[status(thm),theory(equality)],[12,234]),
    [iquote('0:Rew:12.0,234.0')] ).

cnf(389,plain,
    equal(meet(meet(u,join(v,w)),meet(join(u,meet(v,w)),join(w,meet(u,v)))),meet(u,join(v,w))),
    inference(spr,[status(thm),theory(equality)],[13,7]),
    [iquote('0:SpR:13.0,7.0')] ).

cnf(413,plain,
    equal(join(meet(u,join(v,meet(w,u))),meet(meet(w,u),u)),meet(u,join(meet(w,u),meet(u,v)))),
    inference(spr,[status(thm),theory(equality)],[173,13]),
    [iquote('0:SpR:173.0,13.0')] ).

cnf(436,plain,
    equal(meet(join(u,meet(v,join(w,u))),join(join(w,u),meet(u,v))),join(u,meet(join(w,u),join(u,meet(v,join(w,u)))))),
    inference(spr,[status(thm),theory(equality)],[75,13]),
    [iquote('0:SpR:75.0,13.0')] ).

cnf(448,plain,
    equal(join(meet(u,v),meet(v,join(w,meet(u,v)))),meet(v,join(meet(u,v),meet(v,w)))),
    inference(rew,[status(thm),theory(equality)],[10,413,5,11]),
    [iquote('0:Rew:10.0,413.0,5.0,413.0,11.0,413.0')] ).

cnf(449,plain,
    equal(meet(u,meet(join(v,w),meet(join(u,meet(v,w)),join(w,meet(u,v))))),meet(u,join(v,w))),
    inference(rew,[status(thm),theory(equality)],[11,389]),
    [iquote('0:Rew:11.0,389.0')] ).

cnf(459,plain,
    equal(join(u,meet(join(v,u),join(u,meet(w,join(v,u))))),meet(join(v,u),join(u,meet(w,join(v,u))))),
    inference(rew,[status(thm),theory(equality)],[9,436,8,12]),
    [iquote('0:Rew:9.0,436.0,8.0,436.0,12.0,436.0')] ).

cnf(505,plain,
    equal(meet(meet(u,v),join(u,w)),meet(u,v)),
    inference(spr,[status(thm),theory(equality)],[78,144]),
    [iquote('0:SpR:78.0,144.0')] ).

cnf(524,plain,
    equal(join(u,join(v,meet(u,w))),join(u,v)),
    inference(spr,[status(thm),theory(equality)],[10,78]),
    [iquote('0:SpR:10.0,78.0')] ).

cnf(525,plain,
    equal(join(u,join(v,join(meet(u,w),x))),join(u,join(x,v))),
    inference(spr,[status(thm),theory(equality)],[72,78]),
    [iquote('0:SpR:72.0,78.0')] ).

cnf(533,plain,
    equal(meet(u,meet(v,join(u,w))),meet(u,v)),
    inference(rew,[status(thm),theory(equality)],[11,505]),
    [iquote('0:Rew:11.0,505.0')] ).

cnf(745,plain,
    equal(join(meet(u,join(v,w)),meet(w,u)),meet(u,join(v,w))),
    inference(spr,[status(thm),theory(equality)],[158,32]),
    [iquote('0:SpR:158.0,32.0')] ).

cnf(787,plain,
    equal(join(meet(u,v),meet(v,join(w,u))),meet(v,join(w,u))),
    inference(rew,[status(thm),theory(equality)],[10,745]),
    [iquote('0:Rew:10.0,745.0')] ).

cnf(1291,plain,
    equal(meet(u,meet(v,meet(join(u,w),x))),meet(v,meet(u,x))),
    inference(spr,[status(thm),theory(equality)],[178,185]),
    [iquote('0:SpR:178.0,185.0')] ).

cnf(1345,plain,
    equal(meet(join(u,v),meet(w,join(v,meet(w,u)))),meet(w,join(u,v))),
    inference(rew,[status(thm),theory(equality)],[1291,449]),
    [iquote('0:Rew:1291.0,449.0')] ).

cnf(1402,plain,
    equal(join(meet(u,join(v,meet(u,w))),meet(u,join(meet(u,v),meet(x,meet(w,y))))),meet(u,join(v,meet(w,join(u,meet(x,y)))))),
    inference(spr,[status(thm),theory(equality)],[185,1]),
    [iquote('0:SpR:185.0,1.0')] ).

cnf(1441,plain,
    equal(join(meet(u,join(v,meet(u,w))),meet(u,join(meet(u,v),meet(meet(u,w),x)))),meet(u,join(v,meet(meet(u,w),join(u,x))))),
    inference(spr,[status(thm),theory(equality)],[46,1]),
    [iquote('0:SpR:46.0,1.0')] ).

cnf(1500,plain,
    equal(join(meet(u,join(v,meet(u,w))),meet(u,join(meet(u,v),meet(u,meet(w,x))))),meet(u,join(v,meet(u,meet(w,join(u,x)))))),
    inference(rew,[status(thm),theory(equality)],[11,1441]),
    [iquote('0:Rew:11.0,1441.0,11.0,1441.0')] ).

cnf(1501,plain,
    equal(join(meet(u,join(v,meet(u,w))),meet(u,join(meet(u,v),meet(u,meet(w,x))))),meet(u,join(v,meet(u,w)))),
    inference(rew,[status(thm),theory(equality)],[533,1500]),
    [iquote('0:Rew:533.0,1500.0')] ).

cnf(1503,plain,
    equal(meet(u,join(v,meet(w,join(u,meet(u,x))))),meet(u,join(v,meet(u,w)))),
    inference(rew,[status(thm),theory(equality)],[1402,1501]),
    [iquote('0:Rew:1402.0,1501.0')] ).

cnf(1504,plain,
    equal(meet(u,join(v,meet(w,u))),meet(u,join(v,meet(u,w)))),
    inference(rew,[status(thm),theory(equality)],[8,1503]),
    [iquote('0:Rew:8.0,1503.0')] ).

cnf(1925,plain,
    equal(meet(join(u,meet(v,w)),meet(join(w,u),x)),meet(join(u,meet(v,w)),x)),
    inference(spr,[status(thm),theory(equality)],[251,179]),
    [iquote('0:SpR:251.0,179.0')] ).

cnf(1970,plain,
    equal(join(join(u,meet(v,w)),meet(join(u,meet(v,w)),join(w,meet(u,v)))),join(join(u,meet(v,w)),meet(u,join(v,w)))),
    inference(spr,[status(thm),theory(equality)],[13,251]),
    [iquote('0:SpR:13.0,251.0')] ).

cnf(2004,plain,
    equal(meet(join(u,v),meet(w,join(v,meet(x,u)))),meet(join(v,meet(x,u)),w)),
    inference(rew,[status(thm),theory(equality)],[164,1925]),
    [iquote('0:Rew:164.0,1925.0')] ).

cnf(2005,plain,
    equal(meet(join(u,meet(v,w)),v),meet(v,join(w,u))),
    inference(rew,[status(thm),theory(equality)],[2004,1345]),
    [iquote('0:Rew:2004.0,1345.0')] ).

cnf(2006,plain,
    equal(meet(u,join(v,meet(u,w))),meet(u,join(w,v))),
    inference(rew,[status(thm),theory(equality)],[9,2005]),
    [iquote('0:Rew:9.0,2005.0')] ).

cnf(2010,plain,
    equal(join(meet(u,v),meet(v,join(w,meet(u,v)))),meet(v,join(w,meet(u,v)))),
    inference(rew,[status(thm),theory(equality)],[2006,448]),
    [iquote('0:Rew:2006.0,448.0')] ).

cnf(2034,plain,
    equal(meet(u,join(v,meet(w,u))),meet(u,join(w,v))),
    inference(rew,[status(thm),theory(equality)],[2006,1504]),
    [iquote('0:Rew:2006.0,1504.0')] ).

cnf(2048,plain,
    equal(meet(join(u,meet(v,w)),join(w,meet(u,v))),join(meet(u,join(v,w)),meet(w,join(v,u)))),
    inference(rew,[status(thm),theory(equality)],[2034,13]),
    [iquote('0:Rew:2034.0,13.0')] ).

cnf(2065,plain,
    equal(join(u,meet(join(v,u),join(w,u))),meet(join(v,u),join(w,u))),
    inference(rew,[status(thm),theory(equality)],[2034,459]),
    [iquote('0:Rew:2034.0,459.0')] ).

cnf(2086,plain,
    equal(join(meet(u,v),meet(v,join(u,w))),meet(v,join(u,w))),
    inference(rew,[status(thm),theory(equality)],[2034,2010]),
    [iquote('0:Rew:2034.0,2010.0')] ).

cnf(2114,plain,
    equal(join(u,join(meet(v,w),meet(join(u,meet(v,w)),join(w,meet(u,v))))),join(u,join(meet(v,w),meet(u,join(v,w))))),
    inference(rew,[status(thm),theory(equality)],[12,1970]),
    [iquote('0:Rew:12.0,1970.0,12.0,1970.0')] ).

cnf(2115,plain,
    equal(join(u,join(meet(v,join(w,u)),meet(w,v))),join(u,meet(w,v))),
    inference(rew,[status(thm),theory(equality)],[525,2114,2048,524]),
    [iquote('0:Rew:525.0,2114.0,2048.0,2114.0,524.0,2114.0')] ).

cnf(2116,plain,
    equal(join(u,join(meet(v,w),meet(w,join(v,u)))),join(u,meet(v,w))),
    inference(rew,[status(thm),theory(equality)],[10,2115]),
    [iquote('0:Rew:10.0,2115.0')] ).

cnf(2117,plain,
    equal(join(u,meet(v,join(w,u))),join(u,meet(w,v))),
    inference(rew,[status(thm),theory(equality)],[2086,2116]),
    [iquote('0:Rew:2086.0,2116.0')] ).

cnf(2123,plain,
    equal(meet(join(u,v),join(w,v)),join(v,meet(w,join(u,v)))),
    inference(rew,[status(thm),theory(equality)],[2117,2065]),
    [iquote('0:Rew:2117.0,2065.0')] ).

cnf(2163,plain,
    equal(meet(join(u,v),join(w,v)),join(v,meet(u,w))),
    inference(rew,[status(thm),theory(equality)],[2117,2123]),
    [iquote('0:Rew:2117.0,2123.0')] ).

cnf(2258,plain,
    equal(join(meet(u,join(v,join(v,w))),meet(join(v,w),join(v,u))),meet(join(u,v),join(join(v,w),meet(u,v)))),
    inference(spr,[status(thm),theory(equality)],[7,2048]),
    [iquote('0:SpR:7.0,2048.0')] ).

cnf(2259,plain,
    equal(join(meet(u,join(v,join(w,v))),meet(join(w,v),join(v,u))),meet(join(u,v),join(join(w,v),meet(u,v)))),
    inference(spr,[status(thm),theory(equality)],[24,2048]),
    [iquote('0:SpR:24.0,2048.0')] ).

cnf(2356,plain,
    equal(join(meet(u,join(v,w)),meet(join(v,w),join(w,u))),meet(join(u,w),join(v,w))),
    inference(rew,[status(thm),theory(equality)],[58,2259,32,12]),
    [iquote('0:Rew:58.0,2259.0,32.0,2259.0,12.0,2259.0')] ).

cnf(2357,plain,
    equal(meet(join(u,v),join(v,w)),join(v,meet(w,u))),
    inference(rew,[status(thm),theory(equality)],[787,2356,2163]),
    [iquote('0:Rew:787.0,2356.0,2163.0,2356.0')] ).

cnf(2372,plain,
    equal(join(meet(u,join(v,w)),meet(join(v,w),join(v,u))),meet(join(u,v),join(v,w))),
    inference(rew,[status(thm),theory(equality)],[57,2258,251,12]),
    [iquote('0:Rew:57.0,2258.0,251.0,2258.0,12.0,2258.0')] ).

cnf(2373,plain,
    equal(meet(join(u,v),join(u,w)),join(u,meet(v,w))),
    inference(rew,[status(thm),theory(equality)],[787,2372,2357]),
    [iquote('0:Rew:787.0,2372.0,2357.0,2372.0')] ).

cnf(2404,plain,
    ~ equal(meet(a,meet(join(b,c),meet(join(b,d),join(meet(a,c),join(meet(a,d),meet(a,join(b,meet(c,d)))))))),meet(a,join(b,meet(c,d)))),
    inference(rew,[status(thm),theory(equality)],[2373,14]),
    [iquote('0:Rew:2373.0,14.0')] ).

cnf(5648,plain,
    equal(meet(u,meet(v,join(w,meet(meet(u,v),x)))),meet(meet(u,v),join(x,w))),
    inference(spr,[status(thm),theory(equality)],[2006,11]),
    [iquote('0:SpR:2006.0,11.0')] ).

cnf(5671,plain,
    equal(meet(u,join(v,meet(w,meet(u,x)))),meet(u,join(meet(w,x),v))),
    inference(spr,[status(thm),theory(equality)],[185,2006]),
    [iquote('0:SpR:185.0,2006.0')] ).

cnf(5780,plain,
    equal(meet(u,meet(v,join(w,meet(u,meet(v,x))))),meet(u,meet(v,join(x,w)))),
    inference(rew,[status(thm),theory(equality)],[11,5648]),
    [iquote('0:Rew:11.0,5648.0,11.0,5648.0')] ).

cnf(5781,plain,
    equal(meet(u,meet(v,join(meet(u,w),x))),meet(u,meet(v,join(w,x)))),
    inference(rew,[status(thm),theory(equality)],[5671,5780]),
    [iquote('0:Rew:5671.0,5780.0')] ).

cnf(6719,plain,
    equal(meet(join(u,v),meet(join(u,w),x)),meet(join(u,meet(v,w)),x)),
    inference(spr,[status(thm),theory(equality)],[2373,11]),
    [iquote('0:SpR:2373.0,11.0')] ).

cnf(6887,plain,
    ~ equal(meet(a,meet(join(b,meet(c,d)),join(meet(a,c),join(meet(a,d),meet(a,join(b,meet(c,d))))))),meet(a,join(b,meet(c,d)))),
    inference(rew,[status(thm),theory(equality)],[6719,2404]),
    [iquote('0:Rew:6719.0,2404.0')] ).

cnf(7047,plain,
    ~ equal(meet(a,join(b,meet(c,d))),meet(a,join(b,meet(c,d)))),
    inference(rew,[status(thm),theory(equality)],[169,6887,5781]),
    [iquote('0:Rew:169.0,6887.0,5781.0,6887.0')] ).

cnf(7048,plain,
    $false,
    inference(obv,[status(thm),theory(equality)],[7047]),
    [iquote('0:Obv:7047.0')] ).

%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.03/0.12  % Problem  : LAT010-1 : TPTP v8.1.0. Released v2.2.0.
% 0.03/0.13  % Command  : run_spass %d %s
% 0.13/0.34  % Computer : n004.cluster.edu
% 0.13/0.34  % Model    : x86_64 x86_64
% 0.13/0.34  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.13/0.34  % Memory   : 8042.1875MB
% 0.13/0.34  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.13/0.34  % CPULimit : 300
% 0.13/0.34  % WCLimit  : 600
% 0.13/0.34  % DateTime : Thu Jun 30 01:13:38 EDT 2022
% 0.13/0.35  % CPUTime  : 
% 2.07/2.28  
% 2.07/2.28  SPASS V 3.9 
% 2.07/2.28  SPASS beiseite: Proof found.
% 2.07/2.28  % SZS status Theorem
% 2.07/2.28  Problem: /export/starexec/sandbox2/benchmark/theBenchmark.p 
% 2.07/2.28  SPASS derived 4362 clauses, backtracked 0 clauses, performed 0 splits and kept 924 clauses.
% 2.07/2.28  SPASS allocated 70940 KBytes.
% 2.07/2.28  SPASS spent	0:00:01.92 on the problem.
% 2.07/2.28  		0:00:00.03 for the input.
% 2.07/2.28  		0:00:00.00 for the FLOTTER CNF translation.
% 2.07/2.28  		0:00:00.03 for inferences.
% 2.07/2.28  		0:00:00.00 for the backtracking.
% 2.07/2.28  		0:00:01.83 for the reduction.
% 2.07/2.28  
% 2.07/2.28  
% 2.07/2.28  Here is a proof with depth 4, length 86 :
% 2.07/2.28  % SZS output start Refutation
% See solution above
% 2.13/2.32  Formulae used in the proof : n5_1 nr_3 prove_this idempotence_of_meet absorption1 absorption2 commutativity_of_meet commutativity_of_join associativity_of_meet associativity_of_join
% 2.13/2.32  
%------------------------------------------------------------------------------