%------------------------------------------------------------------------------
% File     : Twee---2.4.2
% Problem  : LCL169-3 : TPTP v8.1.2. Released v2.3.0.
% 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 : n009.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 08:17:44 EDT 2023

% Result   : Unsatisfiable 0.13s 0.39s
% Output   : Proof 0.20s
% Verified : 
% SZS Type : -

% Comments : 
%------------------------------------------------------------------------------
%----WARNING: Could not form TPTP format derivation
%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.07/0.12  % Problem  : LCL169-3 : TPTP v8.1.2. Released v2.3.0.
% 0.07/0.13  % Command  : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof
% 0.13/0.34  % Computer : n009.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  : 300
% 0.13/0.34  % DateTime : Fri Aug 25 04:48:51 EDT 2023
% 0.13/0.35  % CPUTime  : 
% 0.13/0.39  Command-line arguments: --set-join --lhs-weight 1 --no-flatten-goal --complete-subsets --goal-heuristic
% 0.13/0.39  
% 0.13/0.39  % SZS status Unsatisfiable
% 0.13/0.39  
% 0.20/0.39  % SZS output start Proof
% 0.20/0.39  Take the following subset of the input axioms:
% 0.20/0.39    fof(axiom_1_2, axiom, ![A]: axiom(implies(or(A, A), A))).
% 0.20/0.39    fof(implies_definition, axiom, ![X, Y]: implies(X, Y)=or(not(X), Y)).
% 0.20/0.39    fof(prove_this, negated_conjecture, ~theorem(implies(implies(p, not(p)), not(p)))).
% 0.20/0.39    fof(rule_1, axiom, ![X2]: (theorem(X2) | ~axiom(X2))).
% 0.20/0.39  
% 0.20/0.39  Now clausify the problem and encode Horn clauses using encoding 3 of
% 0.20/0.39  http://www.cse.chalmers.se/~nicsma/papers/horn.pdf.
% 0.20/0.39  We repeatedly replace C & s=t => u=v by the two clauses:
% 0.20/0.39    fresh(y, y, x1...xn) = u
% 0.20/0.39    C => fresh(s, t, x1...xn) = v
% 0.20/0.39  where fresh is a fresh function symbol and x1..xn are the free
% 0.20/0.39  variables of u and v.
% 0.20/0.39  A predicate p(X) is encoded as p(X)=true (this is sound, because the
% 0.20/0.39  input problem has no model of domain size 1).
% 0.20/0.39  
% 0.20/0.39  The encoding turns the above axioms into the following unit equations and goals:
% 0.20/0.39  
% 0.20/0.39  Axiom 1 (rule_1): fresh2(X, X, Y) = true.
% 0.20/0.39  Axiom 2 (implies_definition): implies(X, Y) = or(not(X), Y).
% 0.20/0.39  Axiom 3 (rule_1): fresh2(axiom(X), true, X) = theorem(X).
% 0.20/0.39  Axiom 4 (axiom_1_2): axiom(implies(or(X, X), X)) = true.
% 0.20/0.39  
% 0.20/0.39  Goal 1 (prove_this): theorem(implies(implies(p, not(p)), not(p))) = true.
% 0.20/0.39  Proof:
% 0.20/0.39    theorem(implies(implies(p, not(p)), not(p)))
% 0.20/0.39  = { by axiom 2 (implies_definition) }
% 0.20/0.39    theorem(implies(or(not(p), not(p)), not(p)))
% 0.20/0.39  = { by axiom 3 (rule_1) R->L }
% 0.20/0.39    fresh2(axiom(implies(or(not(p), not(p)), not(p))), true, implies(or(not(p), not(p)), not(p)))
% 0.20/0.39  = { by axiom 4 (axiom_1_2) }
% 0.20/0.39    fresh2(true, true, implies(or(not(p), not(p)), not(p)))
% 0.20/0.39  = { by axiom 1 (rule_1) }
% 0.20/0.39    true
% 0.20/0.39  % SZS output end Proof
% 0.20/0.39  
% 0.20/0.39  RESULT: Unsatisfiable (the axioms are contradictory).
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