%------------------------------------------------------------------------------
% File : Prover9---2026-6A
% Problem : SEU121+2 : TPTP v9.3.1. Released v3.3.0.
% Transfm : none
% Format : tptp:raw
% Command : prover9 -casc 300 -f /export/starexec/sandbox/benchmark/theBenchmark.p
% Computer : n014.cluster.edu
% Model : x86_64 x86_64
% CPU : Intel(R) Xeon(R) CPU E5-2620 v4 2.10GHz
% Memory : 8046.5625MB
% OS : Linux 6.8.0-71-generic
% CPULimit : 300s
% WCLimit : 300s
% DateTime : Sun Sep 27 08:45:04 AM UTC 2026
% Result : Theorem 0.17s 0.49s
% Output : CNFRefutation 0.17s
% Verified :
% SZS Type : Refutation
% Derivation depth : 7
% Number of leaves : 2
% Syntax : Number of formulae : 21 ( 8 unt; 0 def)
% Number of atoms : 53 ( 0 equ)
% Maximal formula atoms : 7 ( 2 avg)
% Number of connectives : 52 ( 20 ~; 16 |; 12 &)
% ( 1 <=>; 3 =>; 0 <=; 0 <~>)
% Maximal formula depth : 8 ( 4 avg)
% Maximal term depth : 2 ( 1 avg)
% Number of predicates : 3 ( 2 usr; 1 prp; 0-2 aty)
% Number of functors : 4 ( 4 usr; 3 con; 0-2 aty)
% Number of variables : 35 ( 0 sgn 22 !; 4 ?)
% Comments :
%------------------------------------------------------------------------------
fof(d3_tarski,axiom,
! [A,B] :
( subset(A,B)
<=> ! [C] :
( in(C,A)
=> in(C,B) ) ),
file('theBenchmark.p',d3_tarski) ).
fof(t1_xboole_1,conjecture,
! [A,B,C] :
( ( subset(B,C)
& subset(A,B) )
=> subset(A,C) ),
file('theBenchmark.p',t1_xboole_1) ).
fof(t1_xboole_1_neg,negated_conjecture,
~ ! [A,B,C] :
( ( subset(B,C)
& subset(A,B) )
=> subset(A,C) ),
inference(assume_negation,[status(cth)],[t1_xboole_1]) ).
fof(nnf_4,plain,
! [A,B] :
( ( ? [C] :
( ~ in(C,B)
& in(C,A) )
| subset(A,B) )
& ( ! [X0] :
( in(X0,B)
| ~ in(X0,A) )
| ~ subset(A,B) ) ),
inference(fof_nnf,[status(thm)],[d3_tarski]) ).
fof(sk_d3_tarski_sk,plain,
! [A,B] :
( ( ( ~ in(sK0(A,B),B)
& in(sK0(A,B),A) )
| subset(A,B) )
& ( ! [X0] :
( in(X0,B)
| ~ in(X0,A) )
| ~ subset(A,B) ) ),
inference(skolemize,[status(esa),new_symbols(skolem,[sK0]),skolemize(C,sK0(A,B))],[nnf_4]) ).
fof(sk_d3_tarski,plain,
( ! [VAR_0,VAR_1] :
( ~ in(sK0(VAR_0,VAR_1),VAR_1)
| subset(VAR_0,VAR_1) )
& ! [VAR_0,VAR_1] :
( in(sK0(VAR_0,VAR_1),VAR_0)
| subset(VAR_0,VAR_1) )
& ! [VAR_0,VAR_1,VAR_2] :
( in(VAR_2,VAR_1)
| ~ in(VAR_2,VAR_0)
| ~ subset(VAR_0,VAR_1) ) ),
inference(cnf_transformation,[status(thm)],[sk_d3_tarski_sk]) ).
cnf(c_24,plain,
( in(C,B)
| ~ in(C,A)
| ~ subset(A,B) ),
inference(split_conjunct,[status(thm)],[sk_d3_tarski]) ).
cnf(c_25,plain,
( in(sK0(A,B),A)
| subset(A,B) ),
inference(split_conjunct,[status(thm)],[sk_d3_tarski]) ).
cnf(c_26,plain,
( ~ in(sK0(A,B),B)
| subset(A,B) ),
inference(split_conjunct,[status(thm)],[sk_d3_tarski]) ).
fof(nnf_19,plain,
? [A,B,C] :
( ~ subset(A,C)
& subset(B,C)
& subset(A,B) ),
inference(fof_nnf,[status(thm)],[t1_xboole_1_neg]) ).
fof(sk_t1_xboole_1_neg,plain,
( ~ subset(sK1,sK3)
& subset(sK2,sK3)
& subset(sK1,sK2) ),
inference(skolemize,[status(esa),new_symbols(skolem,[sK1,sK2,sK3]),skolemize(A,sK1),skolemize(B,sK2),skolemize(C,sK3)],[nnf_19]) ).
cnf(c_49,negated_conjecture,
subset(sK1,sK2),
inference(split_conjunct,[status(thm)],[sk_t1_xboole_1_neg]) ).
cnf(c_50,negated_conjecture,
subset(sK2,sK3),
inference(split_conjunct,[status(thm)],[sk_t1_xboole_1_neg]) ).
cnf(c_51,negated_conjecture,
~ subset(sK1,sK3),
inference(split_conjunct,[status(thm)],[sk_t1_xboole_1_neg]) ).
cnf(c_132,plain,
( in(A,sK2)
| ~ in(A,sK1) ),
inference(resolve,[status(thm)],[c_49,c_24]) ).
cnf(c_134,plain,
in(sK0(sK1,sK3),sK1),
inference(resolve,[status(thm)],[c_51,c_25]) ).
cnf(c_135,negated_conjecture,
~ in(sK0(sK1,sK3),sK3),
inference(resolve,[status(thm)],[c_26,c_51]) ).
cnf(c_268,negated_conjecture,
( in(A,sK3)
| ~ in(A,sK2) ),
inference(resolve,[status(thm)],[c_24,c_50]) ).
cnf(c_229,negated_conjecture,
~ in(sK0(sK1,sK3),sK2),
inference(resolve,[status(thm)],[c_268,c_135]) ).
cnf(c_269,plain,
in(sK0(sK1,sK3),sK2),
inference(resolve,[status(thm)],[c_134,c_132]) ).
cnf(c_267,plain,
$false,
inference(resolve,[status(thm)],[c_229,c_269]) ).
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.00/0.05 % Problem : SEU121+2 : TPTP v9.3.1. Released v3.3.0.
% 0.00/0.06 % Command : prover9 -casc 300 -f /export/starexec/sandbox/benchmark/theBenchmark.p
% 0.17/0.43 % Computer : n014.cluster.edu
% 0.17/0.43 % Model : x86_64 x86_64
% 0.17/0.43 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.17/0.43 % Memory : 8046.5625MB
% 0.17/0.43 % OS : Linux 6.8.0-71-generic
% 0.17/0.43 % CPULimit : 300
% 0.17/0.43 % WCLimit : 300
% 0.17/0.43 % DateTime : Sat Sep 26 08:37:31 UTC 2026
% 0.17/0.44 % CPUTime :
% 0.17/0.44 % Prover9 (64) version 2026-6A, July 2026, CASC-J13.
% 0.17/0.44 % Process 2667235 was started by sandbox on n014,
% 0.17/0.44 % Sat Sep 26 08:37:31 2026
% 0.17/0.44 % The command was "/export/starexec/sandbox/solver/bin/prover9 -casc 300 -f /export/starexec/sandbox/benchmark/theBenchmark.p".
% 0.17/0.45
% 0.17/0.45 % From the command line: assign(max_seconds, 300).
% 0.17/0.49
% 0.17/0.49 % SZS status Theorem for theBenchmark
% 0.17/0.49
% 0.17/0.49 % Proof 1 at 0.01 (+ 0.01) seconds.
% 0.17/0.49 % Length of proof is 13.
% 0.17/0.49 % Level of proof is 4.
% 0.17/0.49 % Maximum clause weight is 18.000.
% 0.17/0.49 % Given clauses 64.
% 0.17/0.49
% 0.17/0.49 % SZS output start CNFRefutation for theBenchmark
% See solution above
%------------------------------------------------------------------------------