%------------------------------------------------------------------------------
% File : CSE_E---1.7
% Problem : KLE133+1 : TPTP v9.2.1. Released v4.0.0.
% Transfm : none
% Format : tptp:raw
% Command : /export/starexec/sandbox/solver/bin/lemma_parallel_prover %s --lemma-prover /export/starexec/sandbox/solver/bin/cse --final-prover /export/starexec/sandbox/solver/bin/eprover --proof-time %d --global-time-limit %d
% Computer : n007.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 : Tue May 5 04:35:46 PM UTC 2026
% Result : Theorem 1.33s 1.74s
% Output : CNFRefutation 1.33s
% Verified :
% SZS Type : Refutation
% Derivation depth : 12
% Number of leaves : 14
% Syntax : Number of formulae : 67 ( 64 unt; 0 def)
% Number of atoms : 73 ( 72 equ)
% Maximal formula atoms : 3 ( 1 avg)
% Number of connectives : 11 ( 5 ~; 0 |; 4 &)
% ( 0 <=>; 2 =>; 0 <=; 0 <~>)
% Maximal formula depth : 6 ( 2 avg)
% Maximal term depth : 16 ( 3 avg)
% Number of predicates : 2 ( 0 usr; 1 prp; 0-2 aty)
% Number of functors : 11 ( 11 usr; 4 con; 0-2 aty)
% Number of variables : 90 ( 2 sgn 50 !; 0 ?)
% Comments :
%------------------------------------------------------------------------------
fof(left_distributivity,axiom,
! [X1,X2,X3] : multiplication(addition(X1,X2),X3) = addition(multiplication(X1,X3),multiplication(X2,X3)),
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',left_distributivity) ).
fof(domain1,axiom,
! [X4] : multiplication(antidomain(X4),X4) = zero,
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+4.ax',domain1) ).
fof(additive_identity,axiom,
! [X1] : addition(X1,zero) = X1,
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',additive_identity) ).
fof(additive_commutativity,axiom,
! [X1,X2] : addition(X1,X2) = addition(X2,X1),
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',additive_commutativity) ).
fof(domain3,axiom,
! [X4] : addition(antidomain(antidomain(X4)),antidomain(X4)) = one,
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+4.ax',domain3) ).
fof(goals,conjecture,
! [X4] :
( ( ! [X5] : addition(domain(X5),forward_diamond(star(X4),domain_difference(domain(X5),forward_diamond(X4,domain(X5))))) = forward_diamond(star(X4),domain_difference(domain(X5),forward_diamond(X4,domain(X5))))
& ! [X6] : forward_diamond(X4,forward_diamond(X4,domain(X6))) = forward_diamond(X4,domain(X6)) )
=> ! [X7] : addition(forward_diamond(X4,domain(X7)),forward_diamond(star(X4),domain_difference(domain(X7),forward_diamond(X4,domain(X7))))) = forward_diamond(star(X4),domain_difference(domain(X7),forward_diamond(X4,domain(X7)))) ),
file('/export/starexec/sandbox/benchmark/theBenchmark.p',goals) ).
fof(forward_diamond,axiom,
! [X4,X5] : forward_diamond(X4,X5) = domain(multiplication(X4,domain(X5))),
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+6.ax',forward_diamond) ).
fof(domain4,axiom,
! [X4] : domain(X4) = antidomain(antidomain(X4)),
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+4.ax',domain4) ).
fof(right_distributivity,axiom,
! [X1,X2,X3] : multiplication(X1,addition(X2,X3)) = addition(multiplication(X1,X2),multiplication(X1,X3)),
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',right_distributivity) ).
fof(multiplicative_left_identity,axiom,
! [X1] : multiplication(one,X1) = X1,
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',multiplicative_left_identity) ).
fof(multiplicative_right_identity,axiom,
! [X1] : multiplication(X1,one) = X1,
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',multiplicative_right_identity) ).
fof(domain_difference,axiom,
! [X4,X5] : domain_difference(X4,X5) = multiplication(domain(X4),antidomain(X5)),
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+6.ax',domain_difference) ).
fof(right_annihilation,axiom,
! [X1] : multiplication(X1,zero) = zero,
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',right_annihilation) ).
fof(left_annihilation,axiom,
! [X1] : multiplication(zero,X1) = zero,
file('/export/starexec/sandbox/benchmark/Axioms/KLE001+0.ax',left_annihilation) ).
fof(c_0_14,plain,
! [X74,X75,X76] : multiplication(addition(X74,X75),X76) = addition(multiplication(X74,X76),multiplication(X75,X76)),
inference(variable_rename,[status(thm)],[left_distributivity]) ).
fof(c_0_15,plain,
! [X81] : multiplication(antidomain(X81),X81) = zero,
inference(variable_rename,[status(thm)],[domain1]) ).
fof(c_0_16,plain,
! [X64] : addition(X64,zero) = X64,
inference(variable_rename,[status(thm)],[additive_identity]) ).
cnf(c_0_17,plain,
multiplication(addition(X1,X2),X3) = addition(multiplication(X1,X3),multiplication(X2,X3)),
inference(split_conjunct,[status(thm)],[c_0_14]) ).
cnf(c_0_18,plain,
multiplication(antidomain(X1),X1) = zero,
inference(split_conjunct,[status(thm)],[c_0_15]) ).
cnf(c_0_19,plain,
addition(X1,zero) = X1,
inference(split_conjunct,[status(thm)],[c_0_16]) ).
fof(c_0_20,plain,
! [X59,X60] : addition(X59,X60) = addition(X60,X59),
inference(variable_rename,[status(thm)],[additive_commutativity]) ).
fof(c_0_21,plain,
! [X84] : addition(antidomain(antidomain(X84)),antidomain(X84)) = one,
inference(variable_rename,[status(thm)],[domain3]) ).
fof(c_0_22,negated_conjecture,
~ ! [X4] :
( ( ! [X5] : addition(domain(X5),forward_diamond(star(X4),domain_difference(domain(X5),forward_diamond(X4,domain(X5))))) = forward_diamond(star(X4),domain_difference(domain(X5),forward_diamond(X4,domain(X5))))
& ! [X6] : forward_diamond(X4,forward_diamond(X4,domain(X6))) = forward_diamond(X4,domain(X6)) )
=> ! [X7] : addition(forward_diamond(X4,domain(X7)),forward_diamond(star(X4),domain_difference(domain(X7),forward_diamond(X4,domain(X7))))) = forward_diamond(star(X4),domain_difference(domain(X7),forward_diamond(X4,domain(X7)))) ),
inference(assume_negation,[status(cth)],[goals]) ).
fof(c_0_23,plain,
! [X94,X95] : forward_diamond(X94,X95) = domain(multiplication(X94,domain(X95))),
inference(variable_rename,[status(thm)],[forward_diamond]) ).
fof(c_0_24,plain,
! [X85] : domain(X85) = antidomain(antidomain(X85)),
inference(variable_rename,[status(thm)],[domain4]) ).
fof(c_0_25,plain,
! [X71,X72,X73] : multiplication(X71,addition(X72,X73)) = addition(multiplication(X71,X72),multiplication(X71,X73)),
inference(variable_rename,[status(thm)],[right_distributivity]) ).
cnf(c_0_26,plain,
multiplication(addition(X1,antidomain(X2)),X2) = multiplication(X1,X2),
inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_17,c_0_18]),c_0_19]) ).
cnf(c_0_27,plain,
addition(X1,X2) = addition(X2,X1),
inference(split_conjunct,[status(thm)],[c_0_20]) ).
cnf(c_0_28,plain,
addition(antidomain(antidomain(X1)),antidomain(X1)) = one,
inference(split_conjunct,[status(thm)],[c_0_21]) ).
fof(c_0_29,plain,
! [X70] : multiplication(one,X70) = X70,
inference(variable_rename,[status(thm)],[multiplicative_left_identity]) ).
fof(c_0_30,negated_conjecture,
! [X107,X108] :
( addition(domain(X107),forward_diamond(star(esk1_0),domain_difference(domain(X107),forward_diamond(esk1_0,domain(X107))))) = forward_diamond(star(esk1_0),domain_difference(domain(X107),forward_diamond(esk1_0,domain(X107))))
& forward_diamond(esk1_0,forward_diamond(esk1_0,domain(X108))) = forward_diamond(esk1_0,domain(X108))
& addition(forward_diamond(esk1_0,domain(esk2_0)),forward_diamond(star(esk1_0),domain_difference(domain(esk2_0),forward_diamond(esk1_0,domain(esk2_0))))) != forward_diamond(star(esk1_0),domain_difference(domain(esk2_0),forward_diamond(esk1_0,domain(esk2_0)))) ),
inference(shift_quantors,[status(thm)],[inference(skolemize,[status(esa)],[inference(variable_rename,[status(thm)],[inference(fof_nnf,[status(thm)],[c_0_22])])])]) ).
cnf(c_0_31,plain,
forward_diamond(X1,X2) = domain(multiplication(X1,domain(X2))),
inference(split_conjunct,[status(thm)],[c_0_23]) ).
cnf(c_0_32,plain,
domain(X1) = antidomain(antidomain(X1)),
inference(split_conjunct,[status(thm)],[c_0_24]) ).
cnf(c_0_33,plain,
multiplication(X1,addition(X2,X3)) = addition(multiplication(X1,X2),multiplication(X1,X3)),
inference(split_conjunct,[status(thm)],[c_0_25]) ).
fof(c_0_34,plain,
! [X69] : multiplication(X69,one) = X69,
inference(variable_rename,[status(thm)],[multiplicative_right_identity]) ).
cnf(c_0_35,plain,
multiplication(addition(antidomain(X1),X2),X1) = multiplication(X2,X1),
inference(spm,[status(thm)],[c_0_26,c_0_27]) ).
cnf(c_0_36,plain,
addition(antidomain(X1),antidomain(antidomain(X1))) = one,
inference(rw,[status(thm)],[c_0_28,c_0_27]) ).
cnf(c_0_37,plain,
multiplication(one,X1) = X1,
inference(split_conjunct,[status(thm)],[c_0_29]) ).
fof(c_0_38,plain,
! [X92,X93] : domain_difference(X92,X93) = multiplication(domain(X92),antidomain(X93)),
inference(variable_rename,[status(thm)],[domain_difference]) ).
cnf(c_0_39,negated_conjecture,
forward_diamond(esk1_0,forward_diamond(esk1_0,domain(X1))) = forward_diamond(esk1_0,domain(X1)),
inference(split_conjunct,[status(thm)],[c_0_30]) ).
cnf(c_0_40,plain,
forward_diamond(X1,X2) = antidomain(antidomain(multiplication(X1,antidomain(antidomain(X2))))),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_31,c_0_32]),c_0_32]) ).
cnf(c_0_41,plain,
multiplication(antidomain(X1),addition(X2,X1)) = multiplication(antidomain(X1),X2),
inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_33,c_0_18]),c_0_19]) ).
cnf(c_0_42,plain,
multiplication(X1,one) = X1,
inference(split_conjunct,[status(thm)],[c_0_34]) ).
cnf(c_0_43,plain,
multiplication(antidomain(antidomain(X1)),X1) = X1,
inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_35,c_0_36]),c_0_37]) ).
cnf(c_0_44,plain,
domain_difference(X1,X2) = multiplication(domain(X1),antidomain(X2)),
inference(split_conjunct,[status(thm)],[c_0_38]) ).
cnf(c_0_45,negated_conjecture,
antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(X1)))))))))))) = antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(X1))))))),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_39,c_0_32]),c_0_32]),c_0_40]),c_0_40]),c_0_40]) ).
cnf(c_0_46,plain,
antidomain(antidomain(antidomain(X1))) = antidomain(X1),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_41,c_0_36]),c_0_42]),c_0_43]) ).
cnf(c_0_47,plain,
antidomain(one) = zero,
inference(spm,[status(thm)],[c_0_42,c_0_18]) ).
cnf(c_0_48,plain,
addition(zero,X1) = X1,
inference(spm,[status(thm)],[c_0_19,c_0_27]) ).
cnf(c_0_49,negated_conjecture,
addition(domain(X1),forward_diamond(star(esk1_0),domain_difference(domain(X1),forward_diamond(esk1_0,domain(X1))))) = forward_diamond(star(esk1_0),domain_difference(domain(X1),forward_diamond(esk1_0,domain(X1)))),
inference(split_conjunct,[status(thm)],[c_0_30]) ).
cnf(c_0_50,plain,
domain_difference(X1,X2) = multiplication(antidomain(antidomain(X1)),antidomain(X2)),
inference(rw,[status(thm)],[c_0_44,c_0_32]) ).
cnf(c_0_51,negated_conjecture,
antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(X1)))))))) = antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(X1))))),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_45,c_0_46]),c_0_46]),c_0_46]) ).
cnf(c_0_52,plain,
antidomain(zero) = one,
inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_36,c_0_47]),c_0_48]) ).
cnf(c_0_53,negated_conjecture,
addition(antidomain(antidomain(X1)),antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(antidomain(antidomain(X1)))),antidomain(antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(X1))))))))))))))) = antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(antidomain(antidomain(X1)))),antidomain(antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(X1)))))))))))))),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_49,c_0_32]),c_0_32]),c_0_32]),c_0_32]),c_0_32]),c_0_40]),c_0_40]),c_0_40]),c_0_40]),c_0_50]),c_0_50]) ).
cnf(c_0_54,negated_conjecture,
antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(esk1_0))))) = antidomain(antidomain(esk1_0)),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_51,c_0_47]),c_0_52]),c_0_42]),c_0_52]),c_0_42]) ).
fof(c_0_55,plain,
! [X77] : multiplication(X77,zero) = zero,
inference(variable_rename,[status(thm)],[right_annihilation]) ).
cnf(c_0_56,negated_conjecture,
addition(forward_diamond(esk1_0,domain(esk2_0)),forward_diamond(star(esk1_0),domain_difference(domain(esk2_0),forward_diamond(esk1_0,domain(esk2_0))))) != forward_diamond(star(esk1_0),domain_difference(domain(esk2_0),forward_diamond(esk1_0,domain(esk2_0)))),
inference(split_conjunct,[status(thm)],[c_0_30]) ).
cnf(c_0_57,negated_conjecture,
addition(antidomain(antidomain(X1)),antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(X1)),antidomain(multiplication(esk1_0,antidomain(antidomain(X1))))))))))) = antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(X1)),antidomain(multiplication(esk1_0,antidomain(antidomain(X1)))))))))),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_53,c_0_46]),c_0_46]),c_0_46]),c_0_46]),c_0_46]),c_0_46]) ).
cnf(c_0_58,negated_conjecture,
antidomain(multiplication(esk1_0,antidomain(antidomain(esk1_0)))) = antidomain(esk1_0),
inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_46,c_0_54]),c_0_46]) ).
cnf(c_0_59,plain,
multiplication(X1,zero) = zero,
inference(split_conjunct,[status(thm)],[c_0_55]) ).
fof(c_0_60,plain,
! [X78] : multiplication(zero,X78) = zero,
inference(variable_rename,[status(thm)],[left_annihilation]) ).
cnf(c_0_61,negated_conjecture,
addition(antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(esk2_0))))))),antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(antidomain(antidomain(esk2_0)))),antidomain(antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(esk2_0))))))))))))))) != antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(antidomain(antidomain(esk2_0)))),antidomain(antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(antidomain(antidomain(esk2_0)))))))))))))),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_56,c_0_32]),c_0_32]),c_0_32]),c_0_32]),c_0_32]),c_0_40]),c_0_40]),c_0_40]),c_0_40]),c_0_40]),c_0_50]),c_0_50]) ).
cnf(c_0_62,negated_conjecture,
antidomain(antidomain(esk1_0)) = zero,
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_57,c_0_58]),c_0_58]),c_0_18]),c_0_52]),c_0_47]),c_0_59]),c_0_52]),c_0_47]),c_0_19]),c_0_58]),c_0_18]),c_0_52]),c_0_47]),c_0_59]),c_0_52]),c_0_47]) ).
cnf(c_0_63,plain,
multiplication(zero,X1) = zero,
inference(split_conjunct,[status(thm)],[c_0_60]) ).
cnf(c_0_64,negated_conjecture,
addition(antidomain(antidomain(multiplication(esk1_0,antidomain(antidomain(esk2_0))))),antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(esk2_0)),antidomain(multiplication(esk1_0,antidomain(antidomain(esk2_0))))))))))) != antidomain(antidomain(multiplication(star(esk1_0),antidomain(antidomain(multiplication(antidomain(antidomain(esk2_0)),antidomain(multiplication(esk1_0,antidomain(antidomain(esk2_0)))))))))),
inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_61,c_0_46]),c_0_46]),c_0_46]),c_0_46]),c_0_46]),c_0_46]),c_0_46]) ).
cnf(c_0_65,negated_conjecture,
esk1_0 = zero,
inference(rw,[status(thm)],[inference(spm,[status(thm)],[c_0_43,c_0_62]),c_0_63]) ).
cnf(c_0_66,negated_conjecture,
$false,
inference(cn,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[inference(rw,[status(thm)],[c_0_64,c_0_65]),c_0_63]),c_0_52]),c_0_47]),c_0_65]),c_0_65]),c_0_63]),c_0_52]),c_0_42]),c_0_46]),c_0_48]),c_0_65]),c_0_65]),c_0_63]),c_0_52]),c_0_42]),c_0_46])]),
[proof] ).
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.00/0.12 % Problem : KLE133+1 : TPTP v9.2.1. Released v4.0.0.
% 0.00/0.12 % Command : /export/starexec/sandbox/solver/bin/lemma_parallel_prover %s --lemma-prover /export/starexec/sandbox/solver/bin/cse --final-prover /export/starexec/sandbox/solver/bin/eprover --proof-time %d --global-time-limit %d
% 0.16/0.33 % Computer : n007.cluster.edu
% 0.16/0.33 % Model : x86_64 x86_64
% 0.16/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.16/0.33 % Memory : 8042.1875MB
% 0.16/0.33 % OS : Linux 3.10.0-693.el7.x86_64
% 0.16/0.33 % CPULimit : 300
% 0.16/0.33 % WCLimit : 300
% 0.16/0.33 % DateTime : Mon May 4 20:30:39 EDT 2026
% 0.16/0.33 % CPUTime :
% 0.16/0.34 % start to proof: theBenchmark
% 1.33/1.74 % Version : CSE_E---1.7
% 1.33/1.74 % Problem : theBenchmark.p
% 1.33/1.74 % SZS status Theorem for theBenchmark.p
% 1.33/1.74 % SZS output start CNFRefutation
% See solution above
% 1.33/1.75 % Total time : 1.372s
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