%------------------------------------------------------------------------------
% File     : Twee---2.4.2
% Problem  : SWC349-1 : TPTP v8.1.2. Released v2.4.0.
% Transfm  : none
% Format   : tptp:raw
% Command  : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof

% Computer : n005.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 : Thu Aug 31 20:55:06 EDT 2023

% Result   : Unsatisfiable 4.55s 0.98s
% Output   : Proof 4.55s
% Verified : 
% SZS Type : -

% Comments : 
%------------------------------------------------------------------------------
%----WARNING: Could not form TPTP format derivation
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.06/0.11  % Problem  : SWC349-1 : TPTP v8.1.2. Released v2.4.0.
% 0.06/0.12  % Command  : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof
% 0.12/0.33  % Computer : n005.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 : Mon Aug 28 16:38:08 EDT 2023
% 0.12/0.33  % CPUTime  : 
% 4.55/0.98  Command-line arguments: --no-flatten-goal
% 4.55/0.98  
% 4.55/0.98  % SZS status Unsatisfiable
% 4.55/0.98  
% 4.55/0.98  % SZS output start Proof
% 4.55/0.98  Take the following subset of the input axioms:
% 4.55/0.99    fof(clause60, axiom, ![U]: (~ssList(U) | frontsegP(U, nil))).
% 4.55/0.99    fof(co1_4, negated_conjecture, ssList(sk4)).
% 4.55/0.99    fof(co1_5, negated_conjecture, nil=sk3).
% 4.55/0.99    fof(co1_6, negated_conjecture, sk2=sk4).
% 4.55/0.99    fof(co1_7, negated_conjecture, sk1=sk3).
% 4.55/0.99    fof(co1_9, negated_conjecture, ~frontsegP(sk2, sk1)).
% 4.55/0.99  
% 4.55/0.99  Now clausify the problem and encode Horn clauses using encoding 3 of
% 4.55/0.99  http://www.cse.chalmers.se/~nicsma/papers/horn.pdf.
% 4.55/0.99  We repeatedly replace C & s=t => u=v by the two clauses:
% 4.55/0.99    fresh(y, y, x1...xn) = u
% 4.55/0.99    C => fresh(s, t, x1...xn) = v
% 4.55/0.99  where fresh is a fresh function symbol and x1..xn are the free
% 4.55/0.99  variables of u and v.
% 4.55/0.99  A predicate p(X) is encoded as p(X)=true (this is sound, because the
% 4.55/0.99  input problem has no model of domain size 1).
% 4.55/0.99  
% 4.55/0.99  The encoding turns the above axioms into the following unit equations and goals:
% 4.55/0.99  
% 4.55/0.99  Axiom 1 (co1_7): sk1 = sk3.
% 4.55/0.99  Axiom 2 (co1_6): sk2 = sk4.
% 4.55/0.99  Axiom 3 (co1_5): nil = sk3.
% 4.55/0.99  Axiom 4 (co1_4): ssList(sk4) = true2.
% 4.55/0.99  Axiom 5 (clause60): fresh52(X, X, Y) = true2.
% 4.55/0.99  Axiom 6 (clause60): fresh52(ssList(X), true2, X) = frontsegP(X, nil).
% 4.55/0.99  
% 4.55/0.99  Goal 1 (co1_9): frontsegP(sk2, sk1) = true2.
% 4.55/0.99  Proof:
% 4.55/0.99    frontsegP(sk2, sk1)
% 4.55/0.99  = { by axiom 2 (co1_6) }
% 4.55/0.99    frontsegP(sk4, sk1)
% 4.55/0.99  = { by axiom 1 (co1_7) }
% 4.55/0.99    frontsegP(sk4, sk3)
% 4.55/0.99  = { by axiom 3 (co1_5) R->L }
% 4.55/0.99    frontsegP(sk4, nil)
% 4.55/0.99  = { by axiom 6 (clause60) R->L }
% 4.55/0.99    fresh52(ssList(sk4), true2, sk4)
% 4.55/0.99  = { by axiom 4 (co1_4) }
% 4.55/0.99    fresh52(true2, true2, sk4)
% 4.55/0.99  = { by axiom 5 (clause60) }
% 4.55/0.99    true2
% 4.55/0.99  % SZS output end Proof
% 4.55/0.99  
% 4.55/0.99  RESULT: Unsatisfiable (the axioms are contradictory).
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